Answer:
Option B: 
Step-by-step explanation:
The parabola has its concavity downwards, so we need a function in the model:

With a negative value of 'a'
The vertex is (0,0), so we have that:


The x-coordinate of the vertex is given by the equation:



So we have a function in the model:

With a < 0
The only option with this format is B:
