The correct answer is Option B.

Anal cerci in both male and female cockroaches are located at the base of the $10^{\text {th }}$ abdominal segment of their bodies. The cerci are a pair of long, filamentous, sensory appendages that help cockroaches detect movements in the air, which warns them of approaching threats from behind, such as predators. This placement provides an effective mechanism for detecting environmental changes directly around the cockroach's posterior, enhancing their ability to quickly respond and escape threats. The location on the $10^{\text {th }}$ segment is typical and consistent in all cockroaches across different species.