Answer
$$\frac{\cos x}{\sin x}=\cot x$$
$\text{B}$ is the answer here.
Work Step by Step
$$\frac{\cos x}{\sin x}$$
According to the Quotient Identities, we have
$$\cot\theta=\frac{\cos\theta}{\sin\theta}$$
Therefore, $$\frac{\cos x}{\sin x}=\cot x$$
which means we would pick $\text{B}$ as the answer here.