7, 4, 16, , 32, 64, 132, 250

The first term is 2.
The second term is 4. This can be obtained by squaring the first term: $2^2 = 4$.
The third term is 16. This can be obtained by squaring the second term: $4^2 = 16$.

The pattern is that each term is the square of the previous term. To find the fourth term, we square the third term (16).

The calculated next term is 256, which is one of the options ($32, 64, 132, 256$).

The correct option is 256.

The difference between the first and second term is $500 - 475 = 25$.
The difference between the second and third term is $475 - 450 = 25$.
The pattern is a constant decrease of 25 for each subsequent term. This is an arithmetic progression with a common difference of $-25$.

To find the fourth term, subtract 25 from the third term (450).

The calculated next term is 425, which is one of the options ($400, 415, 425$).

The correct option is 425.