A pilot is flying VFR in controlled airspace when he/she notices a receiver failure. Which of the following actions must the pilot take?

1. Squawk 7500 and IDENT.

2. Transmit reports at the scheduled times or positions.

3. Precede the transmitted reports with the phrase "TRANSMITTING BLIND DUE TO RECEIVER FAILURE"

4. Transmit the reports on the frequency in use.

5. Duplicate the reports on the emergency frequency 121.5 MHz.

6. Exit the controlled airspace as soon as practicable.