For the three events $A, B$ and $C$,$P$ (exactly one of the events $A$ or $B$ occurs) = $P$ (exactly one of the events $B$ or $C$ occurs) = $P$ (exactly one of the events $C$ or $A$ occurs) = $p$ and $P$ (all the three events occur simultaneously) = $p^2$,where $0 < p < 1/2$. Then the probability of at least one of the three events $A, B$ and $C$ occurring is

• A
  $\frac{3p + 2p^2}{2}$
• B
  $\frac{p + 3p^2}{4}$
• C
  $\frac{p + 3p^2}{2}$
• D
  $\frac{3p + 2p^2}{4}$