[单选题]

So involved with their computers _______ that leaders at summer computer caps often have to force them to break for sports and games.
A． became the cildren B become the children C had the children become D do the children become

So involved with their computers _______ that leaders at summer computer caps often have to force them to break for sports and games.A． became the cildren B become the children C had the children become D do the children become