code $C$ defined in Exercise $1\mathrm{.}3\mathrm{.}4$ three times

$1\mathrm{.}3\mathrm{.}6$ Repeat each codeword in the code $c.$ Find the closest codewords to the following to form a repetition code of length $9.$ Find the closest codewords to the following received words:

$($a$)001000001$

$($b$)011001011$

$($c$)101000101$

$($d$)100000010$