Glucose and Fructose Are Both C₆H_{1 2}O₆

Glucose and fructose are both C₆H_{1 2}O₆. What is the structural difference between them?

A) Glucose is a five-membered ring and fructose is a six-membered ring.
B) Fructose is a five-membered ring and glucose is a six-membered ring.
C) Glucose is a linear molecule and fructose is a ring.
D) Glucose is found in the boat conformation and fructose is a chair conformation.