Final answer:
The correct equation to calculate the total cost for a group to order an All-You-Can-Eat Lunch is C = G * L, which multiplies the number of people, G, by the cost per person, L.
Step-by-step explanation:
The proper equation to show how much it will cost for any group to order an All-You-Can-Eat Lunch is C = G * L, where C represents the cost, G represents the number of people in the group, and L represents the cost per person for lunch.
This equation implies that the total cost is the product of the number of people in the group and the cost per individual for the meal.
None of the other options a), b), or d) are correct because they either divide the cost per person by the number of people, subtract the number of people from the cost per person, or add the number of people to the cost per person, all of which do not result in a correct calculation of total cost.