When Natasha saves $13 more, she will have enough money to buy a basic MP3 player. The player she wants to buy costs $204, which is three times the cost of the basic player. Which equation could be used to determine n, the number of dollars Natasha has already saved? A: n + 13 = 3(204)
B: 3(n + 13) = 204
C: n + 3(13) = 204
D: 3n + 13 = 204