Which of the following carbanions is most stable?

For the following carbocations,the correct order of stability is:
$I: ^+CH_2-COCH_3$
$II: ^+CH_2-OCH_3$
$III: ^+CH_2-CH_3$

For the following bond cleavages,use curved-arrows to show the electron flow and classify each as homolysis or heterolysis. Identify the reactive intermediate produced as free radical,carbocation,or carbanion.

Among the following carbocations:
$(I)$ $Ph_{2}\stackrel{+}{C} CH_{2} Me$
$(II)$ $Ph CH_{2} CH_{2} \stackrel{+}{C} HPh$
$(III)$ $Ph_{2} CH \stackrel{+}{C} HMe$
$(IV)$ $Ph_{2} C(Me) \stackrel{+}{C} H_{2}$
The order of stability is:

The increasing order of basicity for the following intermediates is (from weak to strong):
$(i)$ $(CH_3)_3C^{-}$
$(ii)$ $H_2C=CH-CH_2^{-}$
$(iii)$ $HC \equiv C^{-}$
$(iv)$ $CH_3^{-}$
$(v)$ $CN^{-}$

Which is the decreasing order of stability?
$(i)$ $CH_3-CH^{+}-CH_3$
$(ii)$ $CH_3-CH^{+}-OCH_3$
$(iii)$ $CH_3-CH^{+}-COCH_3$