A nurse is caring for a client who has had repeated instances of cystitis. When considering the possible progression of the infection, for which symptoms should the client be taught to monitor?

The correct answer is D: Fever. In cystitis, a bacterial infection of the bladder, fever can indicate a more serious kidney infection (pyelonephritis). Dysuria (painful urination) and frequency of urination are common symptoms of cystitis but are not indicative of progression. Pyuria (pus in urine) and hematuria (blood in urine) are common in cystitis but do not necessarily indicate worsening infection. Teaching the client to monitor for fever is crucial as it could signify the infection spreading to the kidneys, requiring immediate medical attention to prevent complications.