Explanation:
As someone has thankfully answered your question. I'll just try to explain that concept to you.
In direct proportion, as the first variable increases or decreases, the second variable also increases or decreases. In mathematical statements, it can be expressed as y = kx. This reads as “y varies directly as x” or “y is directly proportional as x” where k is constant in the equation.
So yes the answer is D
y = -3x