Consider the following statements:

1. Global Depository Receipts (GDR) can be denominated in any freely convertible currency.

2. Real estate investment trusts can engage in both commercial and residential properties.

3. A credit default swap (CDS) is a financial arrangement in which the seller is compensated by the buyer.

4. External Commercial Borrowings (ECB) are classified under four different categories.

Which of the above statements is/are correct?