1. the total revenue from the sale of the product minus its opportunity cost.
2. the total revenue from the sale of that input minus its opportunity cost.
3. the area over the supply curve of the input but under price paid for the product.
4. the area over the supply curve of the product but under the price paid for the product.
Choose the option that yields the correct answer.
Option 2 is the correct answer. Notice that the question refers to the rent to a particular input, not the rent to all inputs. The rent to a particular input is the total revenue from the sale of that input minus that input's opportunity costs. The rent to all inputs is the total revenue from the sale of the product less the opportunity cost of all inputs, which equals the opportunity cost of the product. Options 1 and 4 would both be correct had the question referred to the economic rent to all inputs instead of that to a single input.