Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Speed performance can be improved like strength and endurance by training.
Reason R: Speed has a complex nature as it depends on central nervous system to a considerable degree.

In light of the above statements, choose the most appropriate answer from the options given below
a. Both A and R are correct and R is the correct explanation of A
b. Both A and R are correct but R is NOT the correct explanation of A
c. A is correct but R is not correct
d. A is not correct but R is correct