"If Deb and Sam go to the mall, then it is snowing." Which statement below is logically equivalent?

Question

$\begin {array} {1 1} (A)\;If\: Deb\: and\: Sam\: do\: not \: go\: to\: the \: mall,\: then\: it\: is\: not\: snowing. \\ (B)\;If\: Deb\: and \: Sam \: do\: not\: go\: to\: the\: mall,\: them\: it\: is \: snowing. \\ (C)\;If\: it\: is\: snowing,\: then\: Deb\: and\: Sam\: go \: to \: the\: mall. \\ (D)\;If \: it \: is \: not\: snowing, \: then\: Deb\: and\: Sam\: do\: not\: go \: to\: the \: mall. \end {array}$