Explanation:

Let’s break down each statement:

- Iron and steel plant - Bhilai: Correct. Bhilai, in Chhattisgarh, is famous for its large iron and steel plant. It’s one of the main steel-producing centers in India, so this pairing is spot on.

- Cotton textile - Lucknow: ?? Not quite right. Lucknow is better known for chikankari embroidery rather than large-scale cotton textile mills. Major centers for cotton textile industry in India are places like Mumbai, Ahmedabad, and Coimbatore.

Now, let’s match to the options:

- Option 1: Only II — No, II is wrong.

- Option 2: Neither I nor II — No, I is correct.

- Option 3: Only I — This is the one. Only the first pairing is correct.

- Option 4: Both I and II — Nope, since II isn’t right.

The correct option is Option 3: Only I.