Slow, deliberative writing is recommended when drafting a business message

Sam ranks all of his employees against one another and the grades are distributed highest to lowest. Sam is using a ____ in his review process.

Fill in the blank(s) with the appropriate word(s).

A ________ tax code imposes a larger tax rate on a higher income and a smaller tax rate on lower incomes

A) convex B) concave C) proportional D) flat-rate