A. This is not the best answer. Sensory memory has a biological foundation, and it does not seem to change a great deal with age.
B. This is not the best answer. Episodic memory changes are explained as being influenced by many social experiences that, lacking distinction, run together.
C. This is the best answer. The classical conditioning process of establishing an eye blink to a puff of air is based on neurological function, and consistently shows that older individuals demonstrate slowed reflex learning.
D. This is not the best answer. The basis of this statement is that the brain structure tends to show deterioration with age and that common complaints about memory across the life-span probably are warranted in late life.
E. This is not the best answer. Multiple explanations for aging include biological, psychological, and social issues.