Point "A" in the Above Graph Is

Point "A" in the above graph is

A) efficient since it produces 20 units of output at the lowest possible cost.
B) efficient since it produces 10 units of output at the lowest possible cost.
C) inefficient since it produces 20 units of output at a cost greater than the minimum cost.
D) inefficient since it produces 10 units of output at a cost greater than the minimum cost.