The following diagram depicts the production function of grain, where diminishing average product of labour is assumed. At A the average product of labour is 500,000/800 = 625 kg of grain per farmer. At B the average product of labour is 732,000/1,600 = 457.5 kg of grain per farmer. You know that the grain output for 2,800 farmers is 896,000kg. Read the following statements and select the correct one(s). 多项选择题

In a year with exceptionally good weather conditions, the production function curve will be higher and parallel to the curve above.

If the production curve is an upward-sloping straight line, the average product of labour is constant.

When the labour input is 2,800, the average product of labour is 320 kg.

Diminishing average product of labour is only assumed in some regions of this graph, but not everywhere in the graph.