If $p \equiv$ The switch $S_1$ is closed,$q \equiv$ The switch $S_2$ is closed,$r \equiv$ The switch $S_3$ is closed,then the symbolic form of the following switching circuit is equivalent to:

• A
  $p \wedge (q \vee r) \vee (\neg r \wedge \neg q \wedge p)$
• B
  $p \vee (q \wedge r) \vee (\neg r \vee \neg q \vee p)$
• C
  $p \wedge (q \wedge r) \vee (\neg r \wedge \neg q \wedge p)$
• D
  $p \vee (q \vee r) \wedge (\neg r \vee \neg q \vee p)$