By the time he realizes he ______ into a trap, it'll be too late for him to do anything about it.

1. A.
   walks
2. B.
   walked
3. C.
   has walked
4. D.
   had walked

By the time he realizes he ____into a trap, it’ll be too late for him to do anything about it.

A. walks     B. walked     C. has walked    D. had walked

By the time he realizes he ____ into a trap, it’ll be too late for him to do anything about it.

   A. walks    B. walked  C. has walked   D. had walked

By the time he realizes he ____into a trap, it’ll be too late for him to do anything about it.

A. walks     B. walked     C. has walked    D. had walked

By the time he realizes he ____into a trap, it’ll be too late for him to do anything about it.

A. walks     B. walked     C. has walked    D. had walked