I can't see the answers clearly, but I can see the question. So, I'll just give you a clue/hint.
A stars brightness actually depends on how far it is from your location. If it's far away, it will be dimmer than its counterpart that is closer. To summarize it, if two stars have the same brightness level and one is farther away than the other, the one farther away will appear dimmer than its closer counterpart.
It transmits energy into the medium through its vibration. More energetic vibration corresponds to larger amplitude. The molecules move back and forth more vigorously. The loudness of a sound is also determined by the sensitivity of the ear.
