The $7-$bit ASCII code for the character $$X$$ is:

$1011000$

An even parity check bit is included at the start of this code $($left$-$hand end$),$ so that $8$ bits are transmitted. What will be the transmitted code for the ASCII character $$X$?$

ii$.$If this $8-$bit ASCII character is transmitted using frequency shift keying modulation sketch the transmitted waveform.

iii.If even parity check bits are used, which of the following $8-$bit received ASCII codes are invalid? In each case, give a reason for your choice.

$10110101$

$11110110$

$10100100$