Answer:
A glucose molecule is smaller
Step-by-step explanation:
An artificial membrane has pores of a specific size.
Molecules that are small enough can pass through the pores, but others may be too big.
Glucose (C₆H₁₂O₆) has a certain size, but a sucrose molecule (C₁₂H₂₂O₁₁) is bigger.
If the membrane pores are just the right size, a glucose molecule will be able to pass through, but a sucrose molecule won't.