The correct options are
A The circuit can be closed only when the switch is in ON position.
C The wires should not have any breaks or gaps for circuit to be closed.
An electric circuit can have one or more than one electric cells connected in series (a battery) or parallel as a source. For proper functioning, all the wires of the circuit should be continuous and they should not have any breaks except at the switch which is used to break or connect the circuit. A switch in ON position is necessary for the circuit to be closed. If it is in OFF position, then the circuit is said to be open and no current flows through it.