The answer to one of the following two questions is not correct. Could you please point out which one is wrong? And please show me the right answer! Thanks!

A industry-level cost per unit of output is falling as industry-level output increases Which of the following best describes external economies Question 1 B comparative advantage further reduces the cost to produce a unit of output per firm cost per unit of output is falling within a firm as that firm produces more output producing heavier goods is cheaper when done outside Which of the following is NOT one of the reasons that external economies of scale can occur that we discussed in our lectures? A knowledge spillovers Question 2 B specialized equipment and services labour pooling interconnected synergies