**Core Concept**
The order of sensory blockade of local anesthesia refers to the sequence in which different types of sensory fibers are blocked by a local anesthetic agent. This sequence is crucial in understanding the mechanism of action of local anesthetics and their clinical applications.

**Why the Correct Answer is Right**
The correct order of sensory blockade is as follows: **A** (A-delta fibers), **B** (C fibers), **C** (A-beta fibers). This order is determined by the rate of conduction of the different types of sensory fibers. A-delta fibers, which mediate pain and temperature, are blocked first, followed by C fibers, which transmit pain, temperature, and other sensations. A-beta fibers, which convey touch and pressure, are blocked last. This sequence is due to the differences in the diameter and myelination of the sensory fibers, which affect their conduction velocity.

**Why Each Wrong Option is Incorrect**
* **Option C:** A-beta fibers are not blocked first, as they have a larger diameter and faster conduction velocity than A-delta fibers.
* **Option D:** The sequence of blockade of A-delta and C fibers is not reversed, as C fibers have a slower conduction velocity than A-delta fibers.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the order of sensory blockade is not the same as the order of motor blockade. Motor blockade typically occurs after the blockade of A-delta and C fibers, making it a useful clinical indicator of the effectiveness of local anesthesia.

**Correct Answer:** A. A-delta fibers are blocked first.