Which statement about the observed results of the double-slit experiment is true?

1. Waves that are in phase destructively interfere to create bright bands.
2. Waves that are out of phase constructively interfere to create bright bands.
3. Waves that are in phase constructively interfere to create bright bands.
4. Waves that are out of phase constructively interfere to create bright bands.

3. Waves that are in phase constructively interfere to create bright bands.