Explanation:

- Kunal is elder to Rohit, which implies Kunal is older than Rohit.

- Vivek is younger to Sushma, so Sushma is older than Vivek.

- Kunal is elder to Vivek, meaning Kunal is older than Vivek.

- We lack direct comparison between Rohit and Sushma or Rohit and Vivek.

Given the information, we cannot conclusively determine who is the youngest among Sushma, Rohit, or Vivek as the full hierarchy is not defined.

- Option 1: Sushma - Not enough information.

- Option 2: Rohit - Not enough information.

- Option 3: Vivek - Not enough information.

- Option 4: Cannot be determined - Correct choice as we don't have sufficient data to establish who is the youngest.

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