Explanation:

Let’s break it down:

- Option 1: a minor

A minor can’t sue on their own—they aren’t legally capable. So, they need someone to file the suit for them. That “someone” is called a “next friend.”

- Option 2: a lunatic

Same rule applies here. A person of unsound mind (or “lunatic”—though that term is old-fashioned) isn’t considered fit to represent themselves in court. They also need a “next friend.”

- Option 3: both (a) & (b)

Both minors and persons of unsound mind need a next friend to file a suit for them.

- Option 4: none of the above

This one clearly doesn’t fit, since there are people who *do* need a next friend.

Here’s what this comes down to:

The best answer is Option 3: both (a) & (b).