Answer:
C) 9 Ohms
Explanation:
Initially, the voltage in the circuit is V = 9 V and the current is I = 3.6 A, with three resistors connected in parallel. We can calculate the initial equivalent resistance of the circuit by using Ohm's law:

Now Sally wants to add another resistor in parallel to increase the total current to I = 4.6 A. Since the new resistor is added in parallel, the new equivalent resistance will be:
(1)
where
is the new resistor that should be added.
Again, we can calculate the new equivalent resistance by using Ohm's law:

And substituting this value into eq.(1), we find the value of
:
