Question

—May I open the window to let in some fresh air ?
—___________

1. A.
   Come on
2. B.
   Take care
3. C.
   Go ahead!
4. D.
   Hold on!

Answer 1

C
Come on 来吧，走吧；Go ahead可以，干吧，开始，进行；Take care 小心，当心   Hold on 握住不放，坚持。