Observe the following statements:
$A: f(x) = 2x^3 - 9x^2 + 12x - 3$ is increasing outside the interval $(1, 2)$.
$R: f^{\prime}(x) < 0$ for $x \in (1, 2)$.
Then,which of the following is true?

• A
  Both $A$ and $R$ are true,and $R$ is not the correct reason for $A$.
• B
  Both $A$ and $R$ are true,and $R$ is the correct reason for $A$.
• C
  $A$ is true but $R$ is false.
• D
  $A$ is false but $R$ is true.