Final answer:
The sweet smell in a urinalysis is often caused by ketones, a result of fat metabolism used for energy in place of glucose, and sometimes glucose, when excess sugar is excreted by the kidneys.
Step-by-step explanation:
The observation of a strong "sweet" smell when performing a urinalysis is most often caused by ketones and sometimes glucose. Ketones in the urine, a condition known as ketonuria, produce a fruity odor typically associated with diabetes mellitus, due to the body using fat as an energy source instead of glucose, leading to the production of ketone bodies like acetone. Glucose can also be present in the urine when the kidneys excrete excess sugar, a condition known as glycosuria, which occurs in uncontrolled diabetes, giving the urine a sweet smell.
So, the correct answers are (a) Ketones and (c) Glucose. While ammonia can produce a strong odor, it is usually not described as sweet, and bilirubin does not typically produce a sweet smell in the urine.