A is rational.
The square foot of 4 is 2, and the square root of 25 is 5.
When they are added, you get 7.
7 can be expressed as a fraction, 7/1, so it is rational.
B is irrational.
The square root of 4 is 2, like I said above.
The square root of 2 is an irrational number.
When you add an irrational number, the sum is irrational too.
So, B is irrational.
Therefore, the answer is C.
Hope this helps!