Consider the following statements:
$p$: If voltage increases, then current decreases.
$q$: If voltage does not increase, then current does not decrease.
$r$: If current decreases, then voltage increases.
$s$: If current does not decrease, then voltage does not increase.
Which of the following pairs of statements have the same meaning?

• A
  $p, q$ and $r, s$
• B
  $p, r$ and $q, s$
• C
  $p, s$ and $q, r$
• D
  No pair has the same meaning