Answer:
A
Step-by-step explanation:
monosaccharide is derived from mono, meaning "one", and saccharide, meaning "sugar". The common monosaccharides are glucose, fructose, and galactose. Each simple sugar has a cyclic structure and is composed of carbon, hydrogen and oxygen in ratios of 1:2:1 respectively. Although each sugar mainly exists as a cyclic compound, it is important to note that they are all in equilibrium to a small extent with their linear forms.
While galactose and glucose are composed of six-membered rings, fructose has only five carbon atoms bonded to each other in ring form.