Which of the following carbocations is the most stable?

Which of the following is the most stable carbanion?

The stability order of the following carbocations is:

Arrange the following carbanions in the order of their stability:
$i$. $RC \equiv C^{\ominus}$
$ii$. $C_6H_5^{\ominus}$
$iii$. $R_2C = CH^{\ominus}$
$iv$. $R_3C - CH_2^{\ominus}$

The stability of the following carbocations follows the order:
$I. (CH_3)_3C^{\oplus}$
$II. (CH_3)_2C^{\oplus}(OCH_3)$
$III. CH_3CH_2CH_2CH_2^{\oplus}$
$IV. CH_3CH^{\oplus}CH_2CH_3$

Stability order of the following carbocations is:
$(i)$ $CH_3-C^{+}(CH_3)-CH_2-CH_3$
$(ii)$ $CH_3-CH^{+}-CH_3$
$(iii)$ $CH_3-C^{+}(CH_3)-CH_3$
$(iv)$ $Ph-CH^{+}-CH_3$