Implementation of 4x1 multiplexer and 1x4 demultiplexer using logic gates.

A demultiplexer accepts ......... inputs.
In a multiplexer, the selection of a particular input line is controlled by ___________
If the number of n selected input lines is equal to 2^m then it requires _____ select lines.
Which of the following circuit can be used as parallel to serial converter?
How many select lines would be required for an 8-line-to-1-line multiplexer?