Shout or Shouting??

[neodeep2001]

The only thing survivors can do is shouting for help.

OR

The only thing survivors can do is shout for help.

Which one is correct?

[Philly]

.
"The only thing survivors can do is shout for help." is correct.
.

[Avalon]

agree with philly...the only thing you can do is shout for help!

[kristinita]

Both are acceptable.
The only thing survivors can do is shout for help.( lwhy "to"is omitted?! That's incorrect here)