In a game, each player starts with 100 points. In each round, a player can gain or lose points. After 5 rounds, Alice has 130 points, Bob has 90 points, Charlie has 120 points, and David has 110 points. If David gained 30 points in the first 3 rounds, how many points did he lose in the last 2 rounds?

1. A
   30
2. B
   10
3. C
   40
4. D
   20