Explanation:

Here’s the thing—let’s break down these options:

- Option 1: Mandolin

This is a string instrument, made popular in Indian music by artists like U. Srinivas.

- Option 2: Mridangam

This is the one. P. Mani Iyer was a legendary Mridangam player. He’s known for shaping the modern style of Mridangam in Carnatic music.

- Option 3: Violin

The violin’s huge in Carnatic concerts, but not Mani Iyer’s domain. That’s Lalgudi Jayaraman or T.N. Krishnan territory.

- Option 4: Sarangi

This is a bowed instrument, more prominent in Hindustani music. Has nothing to do with P. Mani Iyer.