Step 1: Understanding Bentham's Hedonistic Calculus.
Bentham's Hedonistic Calculus is a method to quantify the pleasure or pain an action generates, by evaluating several factors: - A. Duration: The time period over which pleasure or pain persists. - B. Fecundity: The potential for an action to yield subsequent pleasures or pains. - C. Purity: The degree to which an action results solely in pleasure, without any accompanying pain. - D. Mortality: The probability of the pleasure or pain leading to death.
Step 2: Conclusion. Duration, Fecundity, Purity, and Mortality are all components of Bentham's Hedonistic Calculus.
Final Answer: \[ \boxed{\text{The correct answer is 3. A, B, C and D.}} \]