Step 1: Understanding the Reaction.
In the given reaction, the nitration of aniline occurs with a mixture of \( \text{HNO}_3 \) and \( \text{H}_2\text{SO}_4 \), resulting in the formation of p-nitroaniline as the major product due to the activating effect of the amino group in the para position.
Step 2: Conclusion.
The correct answer is (C), p-nitroaniline.