Scenario A Renewable Alternative to Fossil Fuels Are Biofuels. Scientists Are

Scenario
A renewable alternative to fossil fuels are biofuels. Scientists are searching for the best plants to use as a source of biofuels. Plant sugars can be fermented into ethanol, and then used as an additive to gasoline. Although it is relatively easy to obtain ethanol in this way, this type of ethanol production competes with the need to produce food. Alternatively, biofuels can be fermented from other plant carbohydrates, such as the cellulose in plant cell walls. This is called cellulosic ethanol production.
-Cellulases are enzymes that are used to break down cellulose. What type of cell would have cell walls that take the LONGEST for cellulases to break down?

A) sclerenchyma
B) parenchyma
C) collenchyma