Which of the following is a rational number

answer:
a. √36
step-by-step explanation:
√36 = rational — the answer to this is 6 and it is a whole number
-√12 = -3.46410161514... — it is repeating without an order so irrational
5/0 = irrational — the denominator cannot be a 0
π = irrational — pi is always irrational