Question

shino

（ウ）で、答えが4になるんですけど、
答えが4になる理由と、他の選択肢がダメな理由を教えて欲しいです

Some boys in our class (
plays
) shogi in the classroom after lunch when it's rainy.
3. playing
4. play
2. to play
(1) I wish I had enough money to buy a violin (
1/using
2 used
2 100
) by a famous musician.
1 1