Answer:
The answer to your question is: a. pentose
Explanation:
a) a pentose is a monosaccharide that has 5 carbons in its structure, if we look at the question the chemical formula only has 5 carbons, then this is the right answer.
b) an oligosaccharide is a group of 2 or more monosaccharides (till 5 or 6) then, it will have 10 or more carbons, this is not the right answer
c) a triose is a monosaccharide that has only three carbons, this is not the right answer.
d) a hexose is a monosaccharide that has 6 carbons, of course this answer is wrong.
e) a polysaccharide is a group of 6 or more monosaccharides, it will have 20 or more carbons, this answer is wrong.