Under a particular set of selection pressure,organisms evolve towards the most efficient reproductive strategy. For example:
$A$) Oysters produce a large number of small-sized offspring.
$B$) Mammals produce a small number of large-sized offspring.
In the light of the above statements,choose the correct option.

• A
  Both $A$ and $B$ are correct.
• B
  Both $A$ and $B$ are incorrect.
• C
  $A$ is correct but $B$ is incorrect.
• D
  $A$ is incorrect but $B$ is correct.