An aircraft is climbing from 4,000 ft to FL100. If the altimeter subscale is set to QNH 1023 hPa, at what indicated altitude should the pilot change the subscale setting to 1013.2 hPa when passing the Transition Altitude of 6,500 ft?

1. 6,500 ft indicated on QNH
2. 10,000 ft indicated
3. 4,500 ft indicated
4. 7,000 ft indicated