Answer:
C. 1/3
Explanation:
Replace each letter with their corresponding value and simplify using the order of operations:
a(b - c*c)
turns into:

You want to remember that order of operations follows the rules of PEMDAS. The operations within the parentheses come first.
1/2 times 1/2 = 1/4
Now we have:

Then 3/4 - 1/4 = 2/4 = 1/2
= 1/3
Therefore your answer is C. 1/3