An analog signal is quantized and transmitted using a PCM

An analog signal is quantized and transmitted using a PCM system. The tolerable error in sample amplitude is 0.5% of the peak-to-peak full scale value. The minimum binary digits required to encode a sample is—

Assume that the amplitude is V_p
given that

δ	= 0.5% of 2V_p
2

1		2V_p		=	0.5	.2V_p		∵δ =	2V_p
2		L			100				L

or
L = 100
or
L = 100 = 2ⁿ ⇒ n = 6.64
So, minimum no. of bits required to encode a sample is 7.
Hence alternative (C) is the correct choice.