Answer:
Option A
Step-by-step explanation:
[tex]D=3ef^2\\[/tex]
we need to make e the subject of the formula so here goes,
On the right side 3 is being multiplied by ef^2 so when it moves to the left side it will divide
[tex]\frac{D}{3}=ef^2[/tex]
now f^2 is also being multiplied by e on the right side so when it moves to the left side it will divide
[tex]\frac{D}{3f^2}=e\\\\[/tex]
