Complete the following sentence by using the appropriate phrasal verb from the given options:

A committee was set up to ________ the problem.

Look in to

The correct answer is Option (2) - Look in to

Reasoning:
The phrasal verb “look into” means to investigate, examine, or study something carefully.

In the sentence —

A committee was set up to ________ the problem.

The correct completion is:
A committee was set up to look into the problem.

That means the committee was formed to investigate or examine the problem.

Other options explained:

• Look for → to search for something.

• Look after → to take care of someone or something.

• Look up → to search for information (in a book, dictionary, etc.) or to visit someone.