问题如下：
An agricultural firm operating in a perfectly competitive market supplies wheat to manufacturers of consumer food products and animal feeds. If the firm were able to expand its production and unit sales by 10% the most likely result would be:
选项：
A.a 10% increase in total revenue.
B.a 10% increase in average revenue.
C.an increase in total revenue of less than 10%.
解释：
A is correct.
In a perfectly competitive market, an increase in supply by a single firm will not affect price. Therefore, an increase in units sold by the firm will be matched proportionately by an increase in revenue.
考点：完全竞争市场下厂商的总收入
解析：在完全竞争的市场条件下，P=MR
虽然题目中的厂商把单位售价提高10%，但是农场品市场是完全竞争市场，厂家只是价格的被动接受者。最后该厂商只能以原来价格卖出产品。但是产量增加了10%,所以总收入增加了10%。B,C选项说法都不对。
这道题两个地方不懂：
1.按照题目意思，TRP=Q×（1+10%）上涨10%，AR=TR/Q=P×Q×（1+10%）/Q×（1+10%）=P，所以B应该是不变，是吗？
2.产量上升，市场上总供给曲线右移，价格下降，这样来看，TR=P×（1+a%）×Q×（1+10%） 而且很可能a＜10%，因为单一厂商影响力有限，那答案应该是C吧。 完全竞争厂商接受市场价格，但是市场价格在题目中确实会发生变化啊
