THIS IS A MATTER OF LIFE AND DEATHThe cost of one pencil is $3, and the total cost of three pencils is $9. Which of the following is true? A. The number of pencils and the total cost are in a proportional relationship because the cost increases with the number of pencils. B. The number of pencils and the total cost are in a proportional relationship because the cost does not increase with the number of pencils. C. The number of pencils and the total cost are in a proportional relationship because the cost of zero pencils is $0, and each pencil costs $3. D. The number of pencils and the total cost are in a proportional relationship because the cost of zero pencils is $0 and it does not increase proportionally with the number of pencils.