Which statements correctly identify limitations of the factors of production?

Which statements correctly identify limitations of the factors of production? Check all that apply.

a - Economies must consider their limitations when answering the three questions of economics.
b - Land is a factor of production that is limited only by the amount available.
c - Capital includes all money and physical facilities needed to create a product.
d - Labor is a factor driven by the size of the population, education, and standard of living.
e - An economy can function well when producing outside its limitations.