Answer:
<em>D. y=-3x</em>
Step-by-step explanation:
<u>Direct Proportion</u>
A direct proportion is a relation between variables where their ratio is a constant value. This means that if y and x are proportional, then:
Where k is the constant of proportionality.
Solving for y:
y=kx
The only choice representing a direct proportion is:
D. y=-3x