The little circle is an invertor (a NOT gate). The logic gate with the inputs connect to a straight line is an AND gate. The logic gate with tinputs connected to a curved line is an OR gate. means OR , means AND , and means NOT . So, the upper input to the gate on the right is
and the lower input to the gate on the right is
So, the output of the gate on the right is
Therefore, answer (C) is correct.