Glucose and Fructose differ in

number of oxygen atoms joined to carbon atoms by double covalent bonds.

number of carbon, hydrogen, and oxygen atoms.

arrangement of carbon, hydrogen, and oxygen atoms.

types of carbon, hydrogen, and oxygen atoms.

number of carbon, hydrogen, and oxygen atoms; types of carbon, hydrogen, and oxygen atoms;
or
and arrangement of carbon, hydrogen, and oxygen atoms.

Its the arrangement of carbon, hydrogen and oxygen atoms.

Double bond comes off the first carbon in glucose and double bond comes off the second one in fructose