If p, q and r are simple propositions, then $(\mathrm{p}\wedge \mathrm{q})\wedge (\mathrm{q}\wedge \mathrm{r})$ is true, then

• A

  p, q and r are true

• B

  p, q are true and r is false

• C

  p is true and q,r are false

• D

  p, q and r are false