Select the correct active voice of the given sentence.

Rohan was pushed into the pool by Karan.

Karan pushed Rohan into the pool. 

The correct active voice of the given sentence "Rohan was pushed into the pool by Karan" is Karan pushed Rohan into the pool.

The passive voice of the sentence is "Rohan was pushed into the pool by Karan." This sentence is in the past tense, which is used to describe an action that happened in the past. The passive voice of the sentence is formed by putting the subject of the active sentence after the verb "to be" and the past participle of the main verb. In this case, the subject of the active sentence is "Rohan" and the main verb is "push." The past participle of "push" is "pushed." So, the passive form of the sentence is "Rohan was pushed into the pool by Karan."

The active voice of the sentence is formed by putting the subject of the passive sentence before the verb and removing the word "by." In this case, the subject of the passive sentence is "Karan," and the verb is "push." So, the active form of the sentence is "Karan pushed Rohan into the pool."

The other options are incorrect because:

• Karan was pushing Rohan into the pool." This sentence is in the past progressive tense, which is used to describe an action that was happening but is not finished. However, the action of pushing Rohan into the pool is finished.
• Rohan had pushed Karan into the pool." This sentence is in the past perfect tense, which is used to describe an action that happened in the past before another action happened. However, in this case, the action of pushing Karan into the pool is not relevant to the present.
• Rohan pushed Karan into the pool." This sentence is the opposite of the passive sentence, and is therefore incorrect.