Robert died on March 2, 2019. Which of the following is an example of income in respect of a decedent (IRD)?

Robert's final paycheck, which was issued two days after his death.

Rental income for the month of April paid to the estate on April 1, 2019. The rent was paid under a contract Robert negotiated on January 10, 2019.

Interest on Robert's checking account, which was earned March 1 and immediately deposited into his account.

Capital gain from the sale of Robert's stock. The estate sold the stock on October 15, 2019 and distributed the proceeds to the beneficiaries.