Could you help me in solving this question, Doctor, as soon as possible, please, and thank you.

Question Holding other factors constant, a company's contribution margin per unit will increase with: 31 Not yet O a. any decrease in the selling price per unit answered O b. None answers given are correct. Marked out of 0.60 O c. any increase in variable cost per unit Flag O d. any decrease in quantity sold. question O e. increase in its total fixed costs