If 'p', 'q', 'r' are statements, then the contrapositive of $$p \rightarrow(q \rightarrow r)$$ is equivalent to

A

$$(p \wedge q)\rightarrow r$$

B

$$(p \rightarrow r)\rightarrow q$$

C

$$(p \vee q)\rightarrow r$$

D

$$(p \rightarrow q)\rightarrow r$$