Explanation:

Rent is a payment made by a tenant to a landlord in exchange for the use of land or property. It is a form of economic rent, which is the payment for the use of a resource that is in fixed supply.

In this question, the correct answer is option 'B', which states that rent will be produced when the elasticity of supply of land is perfectly elastic.

What is elasticity of supply?
Elasticity of supply measures how responsive the quantity supplied of a good or service is to a change in its price. It is determined by factors such as the availability of inputs, production technology, and the time period under consideration.

Why does rent exist?
Rent exists because land is a scarce resource, and its supply is fixed. As the demand for land increases, the price of land also increases. Rent is the payment made by tenants to landlords for the use of land, and it is determined by the interaction of supply and demand.

Explanation of the correct answer:
The correct answer, option 'B', states that rent will be produced when the elasticity of supply of land is perfectly elastic. This means that the quantity of land supplied is extremely responsive to changes in price.

When the elasticity of supply of land is perfectly elastic, it implies that there is an infinite supply of land available at a given price. In this scenario, if the demand for land increases, the price of land will not increase because the supply is perfectly responsive to the increase in demand. As a result, there will be no rent produced because there is no scarcity of land.

Incorrect options:
- Option 'A' states that rent will be produced when the entire land is fertile. However, the fertility of land is not directly related to the production of rent. Rent is determined by the scarcity of land, not its fertility.
- Option 'C' states that rent will be produced when land is mobile. However, mobility of land does not determine the production of rent. Rent is determined by the scarcity of land, not its mobility.
- Option 'D' states that none of the above options are correct. However, as explained above, option 'B' is the correct answer.

Therefore, the correct answer to the question is option 'B', which states that rent will be produced when the elasticity of supply of land is perfectly elastic.