Answer:
The correct option is C) 7/3.
Explanation:
Consider the provided numbers.
If the rational number can be written in the form of
then the rational number will be a terminating decimal.
Now consider the provided options:
Option A) 7/5 can be written as:

Thus it is a terminating decimal.
Option B) 7/4 can be written as:

Thus it is a terminating decimal.
Option C) 7/3 can be written as:

Thus it is not a terminating decimal.
Option D) 7/2 can be written as:

Thus it is a terminating decimal.
Hence the only fraction that must be represented by a non terminating decimal is 7/3.
The correct option is C) 7/3.