In which market structure does one firm sell a good or service with no close substitutes and there is a barrier blocking the entry of new firms?

Points on a production possibilities curve are ________ and ________

A) inefficient; attainable B) inefficient; unattainable C) efficient; attainable D) efficient; unattainable

The lower the price of the good measured on the vertical axis, other thing remaining the same, the flatter the budget line

Indicate whether the statement is true or false