this is a question for factorial ANVOA, please draw graph and explain. what is gradient?

Imagine we conducted a study that found that pedestrians were more likely to give money to a V street beggar if the beggar had a cute and hungry-looking dog with them, and this effect was identical for both male and female pedestrians. If we calculated the difference between men and women in the no dog condition and plotted this value against the difference between men and women in the dog condition, which of the following values is most likely to represent the gradient of our graph? Answer choices A. 22.7 B. 33.8 C. 1 D. 0 Answer: 0