# The stability of carbanions in the following :

is in the order of

$(a)\;iv > ii > iii > i \\ (b)\;i > iii > ii > iv \\(c)\; i > ii > iii > iv \\ (d)\;ii > iii > iv > i$

Higher the number of electron releasing group lower will be the stability of carbanion, and vice versa.
So the order of stability of carbanations is
$i > ii > iii > iv$
Hence c is the correct answer.