PLEASE HELP! Which number is a rational number?

Answer:
C. 17.156
Step-by-step explanation:
A rational number is any integer, fraction, terminating decimal, or repeating decimal. It can be expressed as a ratio of two integers.
The first answer wouldn't make sense, because there is no number times itself that would equal 15. Therefore, it would be irrational. Same goes with the last option.
We can also automatically rule out the second option because it is a nonterminating decimal.