1. Interpret the options

The carbocations shown are:

• A: $CH_3CH_2CH_2^+$ → primary carbocation
• B: $CH_3CH_2^+$ → primary carbocation
• C: $CH_3-\overset{+}{C}H-CH_3$ → secondary carbocation

(Option D is blank.)

2. Rule for carbocation stability

Carbocation stability generally follows:

$3^\circ > 2^\circ > 1^\circ > CH_3^+$

This is because alkyl groups stabilize the positively charged carbon by:

• $+I$ effect (electron-releasing inductive effect)
• Hyperconjugation

3. Compare the given carbocations

• A: $CH_3CH_2CH_2^+$ is a 1° carbocation
• B: $CH_3CH_2^+$ is also a 1° carbocation
• C: $CH_3-\overset{+}{C}H-CH_3$ is a 2° carbocation

A secondary carbocation is more stable than a primary carbocation.

4. Hence

The most stable carbocation among the given options is:

$CH_3-\overset{+}{C}H-CH_3$

So, the correct option is C.

5. Comparison with stored answer

Stored correct answer = C

This matches our derived answer.