A Scientist Is Observing a Membrane Through Which Water and Some

A scientist is observing a membrane through which water and some small hydrophobic molecules can freely pass along a concentration gradient from high to low.However,some sugar molecules are too large to pass through the membrane either way without the assistance of passive transport proteins.Additionally,small Na⁺ ions and some proteins can pass through the membrane against the concentration gradient,but both require the assistance of active transport proteins.What general type of membrane are they observing?

A) impermeable
B) impenetrable
C) semipermeable
D) completely permeable