A study was designed to evaluate the effectiveness of new treatments, including drug (factor D) and non-drug (Factor N) treatments, to reduce the systolic blood pressure of patients determined to have high blood pressure. The researchers identified three drugs (D1, D2, D3) of particular interest. There are numerous non-drug treatments for reducing blood pressure, including various combinations of a controlled diet, exercise programs, biofeedback, and so on. The researchers randomly selected three non-drug treatments (N1, N2, N3) for examination in the study. Combinations of drug and non-drug treatments were randomly assigned to a group of 54 patients. After participating in the program for 2 months, the reduction in systolic blood pressure from the blood pressure readings at the beginning of the program was recorded for each patient. The SAS analysis output of the data is given on the output page. a. This experiment is a two-way factorial treatment design with (circle one) A. both D and N as fixed-effect factors B. both D and N as random-effect factors C. D as a fixed-effect factor and N as a random-effect factor D. N as a fixed-effect factor and D as a random-effect factor