Can someone tell me the answer to this question?

I cannot seem to figure it out

The function $\displaystyle y=\frac{2}{x}$ is decreasing in??

A.(0,$\displaystyle \infty$)

b.($\displaystyle -\infty$,0)

c.(0,2)

d,($\displaystyle -\infty$,$\displaystyle \infty$)

I think B is the correct option but a lot of other people say it's wrong.

Please provide a detailed solution.