Most importantly, musicians can share their works with others. Other people can see their musical ideas and can try and perform them too. Nuances such as tempo, dynamics (loud soft, sweet, "harsh", are just some examples) can be understood even if the composer is not present and there is no recording to listen to.
Financial benefits can be realized from the sale of sheet music, scoring the piece, arranging the piece for bands, orchestras, etc. Conductors can lead an entire musical ensemble through the piece.
A. modem or d. voice input. Not a port because a port allows one to insert a peripheral device but not really communicate. I have no idea what an expansion slot is. It could be d. voice input because this allows a person to hold an audible conversation.
But I'd go for modem because a modem lets you connect devices like laptops, tablets, phones, computers etc. and share data between them. So things like mailing are possible (I THINK)! <span />
Idk maybe at 6:00pm today cuz most of the malls are close. Happy Thanksgiving! :D