Which of the following statements about Public Interest Litigation (PIL) is/are correct?

1. In India, it adheres to the strict requirements imposed by the doctrine of locus standi.

2. Letters to judges may be treated as petitions.

3. M. C. Mehta vs. Union of India was a PIL that expanded the scope of Article 21 and Article 32 of the Constitution of India.

Select the answer using the code given below.