-I haven't heard from Henry for a long time.

-What do you think ________ to him?

A. happening       B. to happen     C. has happened     D. had happened

---I haven't heard from Henry for a long time.

---What do you think ________ to him?

1. A.
   happening
2. B.
   to happen
3. C.
   has happened
4. D.
   had happened

-I haven't heard from Henry for a long time.
-What do you think ________ to him?

1. A.
   happening
2. B.
   to happen
3. C.
   has happened
4. D.
   had happened

 -I haven't heard from Henry for a long time. 

   -What do you think ________ to him?

   A. happening   B. to happen   C. has happened   D. had happened

 -I haven't heard from Henry for a long time. 

   -What do you think ________ to him?

   A. happening   B. to happen   C. has happened   D. had happened