91Ó°ÊÓ

In this, simply use the concept of Prime factorization of the numbers to get the greatest common factor of the given numbers.

Since,

a. The factor of 32are:$32=2×2×2×2×2$

The factor of65 are:$65=5×13$

It has no common factor other than 1.

b. The factor of 34are:$34=2×17$

The factor of69 are:$69=3×23$

It has no common factor other than1 .

c. The factor of 63are:$63=3×3×7$

The factor of91 are:$91=7×13$

It has common factor which is 7other than 1.

d. The factor of26 are:$26=2×13$

The factor of 85are:$85=5×17$

It has no common factor other than 1.

a.$32,65$ : It is not the correct option because it has only one factor .

b.$34,69$: It is not the correct option because it has only one factor .

c.$63,91$: It is the correct option because it has another factor other than .d. $26,85$: It is not the correct option because it has only one factor .