The correct option is C y = 3x
A proportional relationship between input (x) and output (y) can be represented by the equation y = mx
Where, "m"=rate of change=yx
Here, "y" is the amount of bread = 32 kg
"x" is the amount of vegetables= 12 kg
∴ Slope=yx=3212=32×21=3
So, equation for proportional relationship for amount rquired for making a pizza is y = 3x.