Hello!
Let's solve this problem.
Recall that you have to write complete questions in order to get good and correct answers. Anyway, I have found the missing options and the image is attached below.
First of all, you need to know that a rational number is a number that you can write as the quotient of two integers. In other words:
A. is irrational because we know π is an irrational number
B. √7 is irrational because it is the square root of a number that can't be simplified to a whole number
C. 2.22 is a rational number because it can be written as the quotient of two integers 222/100.
When multiplying 2.22 by 0.5 the result is a rational number 111/100.
D. It is irrational because it has non-repeating decimals.
So correct answer is option C.