Market research by Delnorte Ltd has revealed that the maximum demand for product $R$ is 50,000 units each year, and that demand will reduce by 50 units for every $\$ 1$ that the selling price is increased. Based on this information, Delnorte Ltd has calculated that the profitmaximising level of sales for product $R$ for the coming year is 35,000 units. The price at which these units will be sold is:

A. $\$ 100$

B. $\$ 300$

C. $\$ 500$

D. $\$ 700$

E. $\$ 900$