Firm A cаn prоduce а unit оf оutput with 10 hours of lаbor and 5 units of material. Firm B can produce a unit of output with 5 hours of labor and 10 units of material. Firm C can produce a unit of output with 10 hours of labor and 10 units of material. If the prices of labor and material are $10 per hour and $5 per unit, respectively, which of these firms is the most technologically efficient?