Ali is a member of a family that consists of him, his father, his mother and his older brother. Each member of the family has his own mobile phone. Each mobile phone is on a post-paid plan, for which a monthly bill is received at the end of each month. The electricity, on the other hand, is provided to the entire house in general, with one bill is received at the end of each month. The father has recently received the electricity bill for the month, and wishes to do some analysis of electricity consumption. Assuming that the value of the electricity bill is calculated based on a constant monthly subscription fee. In the above information, the cost of electricity to All is: Oa. A direct fixed cost b. An indirect, variable cost OC. A direct, variable cost d. An indirect fixed cost O e. An indirect mixed cost