c$.$

i$.$In error detection and correction methods $($Section $3\mathrm{.}7),$ what is the key difference between the forward error correction $($FEC$)$ and automatic repeat request $($ARQ$)$ schemes?

$(3$ marks$)$

ii$.$The received FEC $75$ message block displayed below uses even parity checks, with the parity bits displayed at the end of each row $($A$$E$)$ and column $(17)$ in the shaded cells $($see Section $3\mathrm{.}7\mathrm{.}1).$ A single bit error has occurred somewhere in this message block.

$$ By checking each row and column, determine the row$-$column grid reference of the bit error.

$$ What change needs to be made to correct the error?

As part of your answer, briefly explain how you located the bit error.