Overheard gossip

Classical Mechanics Level 3

In the figure above, the man is overhearing a conversation while hiding behind the door. He cannot see the other men having the conversation, but he can hear them. Which of the following explains this phenomenon best?

Sound has a higher amplitude than light, which means it has more energy. Sound is transmitted through the solid door, while light is mostly reflected. Sound reflects off the walls better than light, and creates echos. Sound has a longer wavelength than light, which lets it diffract better.