Consider the following statements and select the correct answer from the code given below:

1. Presence of calcium sulphate makes water hard and unfit for use.
2. Diamond is harder than copper and iron.
3. The main component of air is oxygen.
4. Nitrogen is used in the preparation of vegetable ghee.

Code:

A) 1 and 2

B) 3 and 4

C) 1 and 3

D) 2 and 4

This MCQ is part of the UP PSC Previous Year Questions (PYQs) series, focusing on UPPSC Prelims 2003 (GS Paper I)