Microeconomic questions attached below

Determine whether the following statements are TRUE or FALSE. Explain your answer using graphs or examples. a. If a firm has zero elasticity substitution between inputs, then the short-run cost of producing a level of output equals the long-run cost. (5 pts) b. For firms in a competitive market, producing a maximizing profit quantity always means minimizing cost, while the reverse is not true. (5 pts) c. If a firm has a constant return to scale production function, then production capacity is limitless even in the short run. (5 pts) d. In relation to three types of return to scale, the long-run average U-shaped cost never exists. (5 pts)