a
Glucose is soluble in water due to presence of alcohol functional group and extensive hydrogen bonding.

Glucose exist is open chain as well as cyclic forms in its aqueous solution.

Glucose having \(6 \mathrm{C}\) atoms so it is hexose and having aldehyde functional group so it is aldose.

Thus, aldohexose.

Glucose is monomer unit in sucrose with fructose.