In the specific factors model, a country's production possibility frontier is because of ." a straight line; diminishing marginal returns a curved line; diminishing marginal returns a straight line; constant marginal returns a curved line; constant marginal returns a curved line; a limited supply of labor

a curved line; diminishing marginal returns

Explanation:

The specific factor model is one that assumes that a country produces two goods using two factors of production in a perfectly competitive market. That is labour and and capital.

The production possibility frontier is defined as the maximum combination of two products that can be produced by a country. The PPF tends to be curved because of the law of diminishing returns. As more of one factor of production is added it will result in reduced output of the product over time.

answer; signaling;