Okay, let's tackle this question. The user provided a multiple-choice question where the correct answer is about a condition where limb length doesn't increase. The options are missing, but the correct answer is given as an example. Since the options aren't specified, I need to figure out a common scenario where limb length increase isn't observed.

First, the core concept here is likely related to conditions that affect bone growth. Conditions like achondroplasia, which is a form of dwarfism, result in short limbs because of issues with cartilage formation. In contrast, conditions like gigantism or acromegaly cause excessive growth due to excess growth hormone.

The correct answer would be a condition where there's no increase in limb length. For example, in hypothyroidism, especially congenital, there's a decrease in growth, but the limbs might not lengthen. Another possibility is Turner syndrome, where girls have short stature and other features. Alternatively, if the question is about a condition that doesn't cause limb lengthening, like Cushing's syndrome, which can cause truncal obesity but not limb elongation.

Wait, but the question is phrased as "increase in limb length is not found in". So the correct answer would be a condition where limb length doesn't increase. Let me think of specific conditions. For instance, in rickets, there's defective mineralization leading to bowing of bones but not necessarily increased length. Or maybe in osteogenesis imperfecta, where bones are fragile but not longer.

But the most classic example might be achondroplasia, where the problem is in endochondral ossification, leading to short limbs. So if the options include achondroplasia, that would be the correct answer. The other options could be conditions like gigantism or Marfan syndrome, which do cause increased limb length.

Now, the incorrect options would be conditions where limb length does increase. For example, Marfan syndrome causes tall stature with long limbs. Gigantism from GH excess also leads to increased height. Klinefelter syndrome can result in taller stature with long limbs. So if the options include these, they are incorrect.

The clinical pearl here is to remember that achondroplasia is characterized by short limbs due to defective cartilage, which is a high-yield point for exams. The correct answer would be the condition where limb length doesn't increase, so if the options include achondroplasia, that's the right choice.

**Core Concept**
This question tests understanding of developmental disorders affecting limb growth. Conditions like achondroplasia (a form of short-limbed dwarfism) and others disrupt normal endochondral ossification or growth hormone regulation, leading to variable limb length changes.

**Why the Correct Answer is Right**
Achondroplasia, caused by a gain-of-function mutation in the *FGFR3* gene, inhibits cartilage-to-bone conversion in the growth plates. This results in **shortened limbs (rhizomelia)** despite normal trunk growth. The defect in chondrocyte proliferation directly prevents longitudinal bone growth in the limbs.

**Why Each Wrong Option is Incorrect**
**Option A:** *Gigantism* involves excess growth hormone (GH) or IGF-1, causing generalized overgrowth including elongated limbs.
**Option B:** *Marfan syndrome* is

✓ Correct Answer: B. Salter Harris