Answer
There must be a resistor in the box.
Work Step by Step
We can write an expression for the current:
$i = I~sin~(\omega_d t-\phi)$
In this case, we can see that $\phi = -42.0^{\circ}$
When $\phi \lt 0$, then the circuit is largely capacitive.
Therefore, there must be a capacitor in the box.
However, if there is no resistor, then $\phi = -90^{\circ}$
Since $\phi \neq -90^{\circ}$, there must be a resistor in the box.
