So the fraction is 5/20
This means the denominator is 4 time numerator
= 20 = 5 x 4
So from the option u have to pick option A as it is 4/16
This means again the denominator is 4 times the numerator so the value of 5/20 and 4/16 are the same this applies to all numbers.
Back to the point answer is A
Hope u understood
If not comment and I will explain in more detail