I don't understand this, please explain as much as possible.

A multiplexer (MUX) is made of a decoder and a selector switch. Design a 4-1 MUX that outputs: - Input a on address 1 Input b on address 5 - Input c on address2 - Input d on address4 Label the decoder inputs (address) as xyz (x is MSB) and outputs as L, M, N, 0. Show the truth tables and output expressions for decoder and MUX. Draw the full MUX circuit