医学选择题

A neuron
当然是神经系统感受来自体内和体外（主要是皮肤skin）的变化和刺激(stimuli)，并使人体做出相应反应。

选 A

Sensory input: The nervous system receives sensory information from millions of SENSORY RECEPTORS that detect changes (stimuli) inside and outside of the body. The sensory stimulus is converted to a nerve impulse by a sensory NEURON, which transmits the nerve impulse to the central nervous system.

选A
能够感受身体内外的变化的器官当然是神经细胞了。