Gerund or infinitine

1.

1. It's late. I must … now.
a) go b) to go c) going
2. Ann is always in the kitchen. She
enjoys…
a) cook b) to cook c) cooking
3. Would you like … to dinner on Sunday?
a) come b) to come c) coming
4. Could you … me with this bag, please?
a) help b) to help c) helping