A i would go with

answer is coorect, pls explain..!!

Correct answer should compare like items i.e "power-generating apparatus of a" to "power-generating apparatus of a
like compares one person to one person..
like compares group to group
So keeping this in mind number and what is being compared A matches

A does that
B is wrong because power generating apparatus is compared with hybrid car
C.. one apparatus is compared to a lot of apparati.. wrong in number
D.. apparati is comparad to that of hybrid car's .. is like that of (something of hybrid car)... not correct
E. that of hybrid cars... not good... that of hybrid car or those of hybrid cars..

With a comparison, we need to maintain parallel form. The wording "that of" accomplishes this, so A, D, and E are okay. B does not have "that of" and C ruins parallel form by giving us a plural noun in the second half of the comparison.

E uses the plural form "depend", which creates an agreement error.

D uses "car's" to indicate possession, but that is redundant because we already used "that of" to accomplish the same purpose.

A is best.