Answer:
Option (c) is correct.
a = 3 and b = 4
Explanation:
Given :
We have to find the values of a and b and choose the correct options from the given options.
Consider

We first factorize 648 that is writing 648 as products of its prime factors.
648 can be written as 8 × 81
breaking 8 as product of 2 and 81 as product of 3.
We get,

Also,
Thus, a = 3 and b = 4
Option (c) is correct.