How many 512X8 ROMs are needed to make a 2048X64 ROM and wha

How many 512X8 ROMs are needed to make a 2048X64 ROM and what kind of decoder should be used? (Only use the 512X8 ROMs)

a. # of 512X8 ROMs : 32, type of decoder : 2X4

b. # of 512X8 ROMs : 64, type of decoder : 3X8

c. # of 512X8 ROMs : 16, type of decoder : 3X8

d. # of 512X8 ROMs : 32, type of decoder : 1X2

2^n 512X8 ROMs are needed to make 2048X64 ROM

where n=2048/512=4

2^4=16 512X8 ROMs are needed to make 2048X64 ROM and it is 3*8 decoder (3 inputs and 1 selected line)

Option-(c) is correct