We have to identify the rational number.
Any number that can be expressed as a fraction is a rational number.
In this case the options are:
A. The square root of 3. This does not have a solution with finite number of decimals, so it can not be expressed as a fraction. Then, it is not rational.
B. The square root of 36, unlike the square root of 3, does have a rational solution: 6. So the square root of 36 is a rational number.
C. The square root of 7. This does not have a solution with finite number of decimals, so it can not be expressed as a fraction. Then, it is not rational.
D. The number π has an infinite number of decimals, so it can not be represented as a fraction. Thn, it is not a rational number.
nswer: O√36 [ption B]