Consider the following statements about the Kushan Empire’s rule in Punjab:

1. The Kushanas were the first rulers in India to issue gold coins on a large scale.

2. The Kushan capital in Punjab was Peshawar, known as Purushapura.

3. Kanishka convened the Fourth Buddhist Council in Jalandhar, Punjab.

4. The Kushanas introduced the Gandhara school of art, which blended Indian and Hellenistic styles.

Which of the above statements are correct?