Physics question help please needed

An Envelope Detector is used to demodulate a conventional AM signal defined by the following equation: y(t) = [6.4 + 11.6cos(6000πt)] cos(1,548,000πt) volts. If C = 3 nF, what values of Rs and Rl would be suitable?
A Rs = 25 ohm and Rl = 5 k-ohm
B Rs = 200 ohm and Rl = 8 k-ohm
C Rs = 151 ohm and Rl = 50 k-ohm
D Rs = 40 ohm and Rl = 30 ohm
E Rs = 8 k-ohm and Rl = 40 ohm

Which is the correct one 1 if u can show working out that will be great thanks