please explain . every little step. the answer is B but I don't know how to get that. to match the graph .

10. (10 points) Which of the following portfolios has its payoff represented by the figure below? 201. 10i 101 20 0 20 30 40 50 ib) Slock Price A. long call with strike 20 and long put with strike 30 B. long call with strike 30 and short put with strike 20 C. short call with strike 20 and long put with strike 30 D. short put with strike 20 and long put with strike 30 E. short call with strike 30 and short put with strike 20