Fructose and Galactose Both Have Six Carbon Atoms,twelve Hydrogen Atoms

Fructose and galactose both have six carbon atoms,twelve hydrogen atoms and six oxygen atoms,just like glucose.A friend of yours says: "Since those sugars have the same number of atoms,they should have the same name." You answer: "While they do have the same number and type of atoms,

A) they are all polysaccharides and have slightly different functions within organisms and therefore have different names."
B) they are named differently because of their quaternary structures,which is very important in carbohydrates,especially glucose."
C) they are named differently because when heated above their optimal temperature they become denatured and will not react with their substrates."
D) they are named differently because they are involved in different DNA nucleotide formation."
E) they are named differently because they are alternate forms of the monosaccharide,glucose."