Which of the following statements best explains why urinary tract infections are more common in females than in males?

A. Males have more acidic urine, which is effective in eliminating bacteria from the urinary tract.
B. The presence of estrogen in the lining of the female reproductive tract makes the mucous membranes more prone to infection.
C. Bacteria from the vagina commonly enter the female urethra.
D. The female urethra is shorter than those in males, more easily allowing bacteria to enter the rest of the urinary tract.