Converts sound to a signal in a telephone

a. transmitter

b. receiver

c. radio

d. television

b. receiver.

hope this helps:)sorry if it doesnt

they start with the same

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .