Two liquids $A$ and $B$ have $\theta_{A}$ and $\theta_{B}$ as contact angles in a capillary tube. If $K = \cos \theta_{A} / \cos \theta_{B}$,then identify the correct statement:

• A
  $K$ is negative,then liquid $A$ and liquid $B$ have convex meniscus.
• B
  $K$ is negative,then liquid $A$ and liquid $B$ have concave meniscus.
• C
  $K$ is negative,then liquid $A$ has concave meniscus and liquid $B$ has convex meniscus.
• D
  $K$ is zero,then liquid $A$ has convex meniscus and liquid $B$ has concave meniscus.