Final answer:
Sexually active women are at the highest risk for urinary tract infection due to the short length and close proximity of the female urethra to the anus, which can result in infections of the urinary tract by fecal bacteria.
Step-by-step explanation:
The group at the highest risk for urinary tract infections (UTIs) is sexually active women. UTIs are more common in women compared to men due to the short length and close proximity of the female urethra to the anus, which can result in infections of the urinary tract by fecal bacteria. Good hygiene and urination after sexual activity can help reduce the risk of UTIs.