Which resistors in the circuit must have the same amount of energy per unit charge across them?
a. c and d
b. a and b
c. a and d
d. b and c

D.B and C

Explanation:

We have to find that which of the given is having same amount of energy per unit charge.

So we know that energy per unit charge is defined as potential.

so here we have to find in this circuit that which of the given resistors are at same potential.

So here we can see that resistance B and C are parallel to each other in this circuit and all the resistors which are in parallel to each other are always having same potential.

So B and C are having same potential energy per unit charge

the answer is a i think

frequency or wavelenth of em radiation in a vacuum