The most probable and the most likely answer that you would get in asking this question would be domain.
As for stating it as a taxonomic group, it is more appropriate to refer to it as category, but there is no arguing that both words can be interchanged so just take that as a personal preference. Domain would be referred to in modern taxonomic category as the category that includes the kingdoms and all the other levels of the taxonomic hierarchy.
Answer:
A. The urinary tract infections or the UTI refers to the infections found in the urethra, kidney, and bladder. The infection generally takes place because of the entry of bacteria that may invade the urethra or bladder. This leads to irritation in the bladder primarily in women.
B. In urinary tract infections, primarily the kidneys, bladder, and ureter get affected. The infection is most commonly caused by E.coli and Klebsiella species. In women, the urethra is generally shorter in comparison to males, thus, bacteria can easily invade the bladder most probably at the time of sex.
The mentioned bacteria are usually found in the digestive tract and may move into the urinary system, mainly at the time of sexual intercourse.
