since 4 data lines .we can have 16 bit in one line. since memory can be byte addressable in general in line we have 2 byte
so one chip size will be = number of address lines*line size
= 2^12*2B= 2^13B
and we have 8 such memory chips
so total size will be=2^3*2^13B=2^16B=64KB
option d is correct