The designer himself is not sure whether this software is appropriate ______ children under 12 years old.

A．Many people go to cinema to have an interesting movie as a substitute.
B．Many people go out shopping as a way to change their habit.
C．Many people go to the bookstore to have a good book as a substitute.
D．Many people go out shopping without a second thought when having pressure.

A.where
B.what
C.which
D.that