Plants use cellulose for their cell walls. Basically, fiber is cellulose . Cells walls are fiber.
This justifies what answer for what question? Q & A: 
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What are cell walls made of?
Options:
- (A) fossils
- (B) peat
- (C) moss
- (D) cations
- (E) Carbon
- (F) Fiber
- (G) Fungi
- (H) sodium
(F)
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