Final answer:
b. Bile pigment
A greenish hue in a urine sample could be caused by the presence of bile pigments, typically indicative of jaundice or a reaction to certain medications or medical dyes.
Step-by-step explanation:
If a urine sample has a greenish hue, one possible cause could be a bile pigment presence. This coloration can occur if a person is suffering from conditions like jaundice, where there is an excessive excretion of bile pigments in the urine.
In addition to bile pigments, such a color could sometimes be the result of a drug reaction, where certain medications or medical dyes can alter the color of urine. Conditions such as myoglobinuria, resulting from muscle breakdown, typically cause darker, brown urine, not greenish.
Conversely, oliguria, which refers to the production of abnormally small amounts of urine, does not inherently change urine color.