I can't see the blackboard.Because a tall boy is ___me.A.in

I can't see the blackboard.Because a tall boy is ___me.A.in the front of B.in front of C.beside D.Behind
这个题为什么选in front of,而不选in the front of.
而且：
in front of就是指在某物的前方.
in the front of是指在某物的内部靠前的地方.
比如sit in the front of the classroom.指坐在教室前排的.
sit in front of the classroom指坐在教室前面（教室外面的前面.）
这个题也是坐在前排的啊~