It should be a.), all plant cells have a cell wall made of cellulose, which acts as exoskeleton and makes them so stable. However on a bigger level this plant cells can also form cellulose fibers, so that c.) is not completely false :)
Answer:

Step-by-step explanation:
Given the function: 
f(x) =number of days it would take to complete the project
x =number of full-time workers.

The domain of a function is the complete set of possible values of the independent variable.
In this case, the independent variable is x, the number of full-time workers. We have shown that x cannot be zero as there must be at least a worker on ground.
Therefore, an appropriate domain of the function f(x) is the set of positive integers (from 1 to infinity).

Answer:
I think it's A: Similar - AA
Step-by-step explanation:
We know that ∠K≅∠N & ∠L≅∠P, so that gives us 2 sets of congruent angles