XYZ Company uses the high low method to analyze the mixed cost. According to the cost formula derived, the total fixed cost is $10,000. Total cost at the high level of activity was $70,000 and at the low level of activity was $25,000. If the low level of activity was 2,500 units, what was the high level of activity in units? Select one: O a. 7,000 O b. None of the answers given O c. 11,000 O d. 10,000 e. 10,500