A black box has two input connections and two output connections. With a 12-V rms, 60-Hz sine

Question:

A “black box” has two input connections and two output connections. With a 12-V rms, 60-Hz sine wave across the inputs, the output is a 6.0-V, 60-Hz sine wave leading the input voltage by 45°. Design a circuit that could be in the “black box.”