Can you explain to me how this is the answer, please and thank you!

(8) Given the 95% confidence interval [20, 30] what is the sample mean and the margin of error? (A) I = 25, MoE = 10 (B) = = 25, MoE = 5 (C) * = 20, MoE= 10 (D) = = 30, MoE= -10 (E) = = 50, MoE = 5