Final answer:
The correct answer is option B) Once an infant is weaned, the mother can become pregnant again, thus reducing the interbirth interval
Step-by-step explanation:
Biological anthropologists have proposed that humans are weaned earlier than other primates because this life history pattern allows for a shorter interbirth interval. This is based on the idea that, once an infant is weaned, the mother is able to become pregnant again, potentially leading to more offspring over the course of her life.
This strategy could have evolved as a response to the energetic demands of the human brain, which is large relative to body size and requires significant resources to develop properly. Additionally, as hunter-gatherers, early humans would have benefited from being able to balance the need for parental care with the need to secure enough resources to support their offspring.