**Core Concept**
Active management of the third stage of labor is a crucial step to prevent postpartum hemorrhage (PPH), which is the leading cause of maternal mortality worldwide. This process involves administering uterotonic agents, controlled cord traction, and uterine massage to ensure the uterus contracts and bleeding is minimized.

**Why the Correct Answer is Right**
Active management of the third stage of labor is essential in all cases to prevent PPH. Uterotonic agents, such as oxytocin, help stimulate uterine contractions, while controlled cord traction and uterine massage facilitate placental delivery and uterine involution. This comprehensive approach significantly reduces the risk of PPH.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as active management of the third stage of labor is crucial in all cases to prevent PPH.
* **Option B:** This option is incorrect as it implies that active management of the third stage of labor is not necessary in certain cases. However, the World Health Organization recommends active management in all births.
* **Option C:** This option is incorrect as it is unclear what this statement means and does not provide a valid exception to active management of the third stage of labor.

**Clinical Pearl / High-Yield Fact**
A mnemonic to remember the key steps in active management of the third stage of labor is "UTERUS": Uterotonic agent, Traction on the cord, Uterine massage, and Rest.

**Correct Answer: B.**