**Core Concept**
During puberty, the growth spurt in boys is primarily driven by the increase in growth hormone (GH) secretion from the anterior pituitary gland, leading to the activation of the GH-IGF-1 axis. This hormonal cascade stimulates the growth plates in the long bones, resulting in an increase in height.

**Why the Correct Answer is Right**
The GH-IGF-1 axis plays a crucial role in regulating growth and development during puberty. Growth hormone stimulates the production of insulin-like growth factor 1 (IGF-1) in the liver and other tissues, which in turn promotes the proliferation and differentiation of chondrocytes in the growth plates. This leads to an increase in the length of the bones, resulting in the growth spurt characteristic of puberty. The growth plates in the long bones, such as the femur and humerus, are responsible for this increase in height.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the growth spurt in boys during puberty.
**Option B:** This option is incorrect because it does not specify the underlying hormonal mechanism driving the growth spurt.
**Option C:** This option is incorrect because it is not a specific or accurate description of the growth spurt in boys during puberty.

**Clinical Pearl / High-Yield Fact**
The growth spurt in boys typically occurs between the ages of 10 and 14, with the average increase in height being around 20 cm (8 inches) during this period. This growth spurt is a normal and essential part of puberty, and any significant deviations from this pattern should prompt further evaluation.

**Correct Answer: C. 20 cm (8 inches)**