What is an example of a physical indicator of potential sexual assault victims?

The presence of a sexually transmitted infection (STI) can serve as a significant physical indicator of potential sexual assault victims. When an individual contracts an STI, it is often a result of sexual activity, and in the context of sexual assault, this can indicate that non-consensual sexual activity has occurred. The medical examination of sexually assaulted individuals often includes testing for STIs as these infections can provide important medical evidence and can signal the need for further investigation.

In contrast, the other options such as increased socialization, good posture, and a positive demeanor do not provide any physical evidence related to sexual assault. Increased socialization might reflect various factors in a person's life and does not indicate assault risk or experience. Good posture and a positive demeanor can be associated with a person's general mental state or physical health, rather than being direct indicators of sexual violence. Therefore, the contraction of an STI is the only choice that directly relates to the physical implications of sexual assault.