Which Statement Is True Concerning Curvilinear Variable Cost Functions

Multiple Choice

Which statement is true concerning curvilinear variable cost functions?

A) Curvilinear variable cost functions have both fixed and variable components which vary in constant proportion.
B) Curvilinear variable cost functions increase in logical steps which vary in constant proportion.
C) Curvilinear variable cost functions always involves long-term assets which vary in constant proportion.
D) Curvilinear variable cost functions are where costs vary with the volume of activity,but not in constant proportion.