3, 4, 7, 8, 11, 12, … What number should come next?

7
10
14
15

The answer is $\boxed{15}$.

This is an arithmetic sequence with a common difference of $3$. In other words, each term is $3$ more than the term before it. So, the next term after $12$ is $12 + 3 = \boxed{15}$.

Option A is incorrect because $7$ is the second term in the sequence, not the next term.

Option B is incorrect because $10$ is not in the sequence.

Option C is incorrect because $14$ is not in the sequence.