C35: A xenon arc lamp is covered with an interference filter that only transmits light of 400-nm wavelength. When the transmitted light strikes a metal surface, a stream of electrons emerges from the metal. If the intensity of the light striking the surface is doubled,

1. more electrons are emitted in a given time interval.

2. the electrons that are emitted are more energetic.

3. both of the above.

4. neither of the above.