A. The place can be used by children.
B. The place is used by children always.
C. The place could always be used by the children.
D. The place has been used by children always.
The given sentence contains one of Model verb (Model Verb = will, shall, can, may, might, could, might, must, would). It is in active voice.
Rule :
Subject + Model verb + be + V3 + Optional Objects
