90, 180, 12, 50, 100, 200, ?, 3, 50, 4, 25, 2, 6, 30, 3

150
175
225
250

The answer is $\boxed{175}$.

The sequence is generated by multiplying the previous number by 2 and then subtracting 12. For example, the first number is 90, which is 2 times 45 minus 12. The second number is 180, which is 2 times 90 minus 12. The third number is 12, which is 2 times 6 minus 12. And so on.

The next number in the sequence is 175, which is 2 times 87.5 minus 12.

Here is a table showing the first few numbers in the sequence:

Number | Formula
——- | ——–
90 | 2 * 45 – 12
180 | 2 * 90 – 12
12 | 2 * 6 – 12
50 | 2 * 25 – 12
100 | 2 * 50 – 12
200 | 2 * 100 – 12
175 | 2 * 87.5 – 12

Option A, 150, is not in the sequence because it is not a multiple of 2.

Option B, 175, is in the sequence because it is a multiple of 2 and it is 12 less than the previous number in the sequence.

Option C, 225, is not in the sequence because it is not a multiple of 2.

Option D, 250, is not in the sequence because it is not a multiple of 2 and it is 12 less than the previous number in the sequence.