I don't understand how they got this answer- if your answer is different then please still show me step by step:

Data below is applicable to questions 1 & 2. You have been approached by a trader that requires assistance on margin-buying and short-selling on Discovery Ltd.. He has provided you with the current Bid and Ask price of Discovery Ltd. as well as a forecast of the price in 1 month time (see table below). Assume a portfolio value/short position of R10 000.00: Bid Today 1 Month R91.9 R106.6 Ask R92.82 R107.67 Question 1 Calculate the return assuming that shares are purchased on margin, where the margin amount is 80%, loan 20% and maintenance margin is 40%. A) -7.73% B) -6.44% C) -5.41% D) -7.53% E) -5.22% Correct answer is B