The correct answer is $\boxed{\text{C. }58, 66}$.
The sequence is $9, 16, 23, 30, 37, 44, 51, …$. Each number in the sequence is $7$ more than the previous number. Therefore, the next number in the sequence is $51 + 7 = \boxed{58}$. The next number after that is $58 + 7 = \boxed{66}$.
Option A is incorrect because $59$ is not $7$ more than $51$. Option B is incorrect because $56$ is not $7$ more than $51$. Option C is correct because $58$ is $7$ more than $51$ and $66$ is $7$ more than $58$. Option D is incorrect because $58$ is not $7$ more than $56$. Option E is incorrect because $54$ is not $7$ more than $51$.