问题


There is a single choice question about high school microeconomics. Answer the question by replying A, B, C or D.
Question: Which of the following is a characteristic of monopoly?
A. A single firm in the industry.
B. Price equal to marginal revenue.
C. Perfectly elastic demand curve.
D. Weak barriers to entry.
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

A. A single firm in the industry.		 A
deepseekr1

Answer: A. A single firm in the industry.

**Explanation**:
- **A** is correct because a monopoly is defined by having only one firm dominating the entire market.
- **B** is incorrect since in a monopoly, price exceeds marginal revenue due to the downward-sloping demand curve.
- **C** is wrong as a perfectly elastic demand curve describes perfect competition, not monopoly.
- **D** is false because monopolies rely on strong barriers to entry to maintain their market power.		 A
gpto1 A A
GPT-4o A. A single firm in the industry. A
llama3.1-70B-Instruct

A		 A
llama3.1-405B-Instruct

A. A single firm in the industry.		 A
DeepSeek-Coder-V2 A A
Qwen2-72B-Instruct A. A single firm in the industry. A
baichuan4 A. A single firm in the industry. A
doubao A

In a monopoly, there is only one firm in the industry, which is a key characteristic. In a monopoly, price is not equal to marginal revenue (so B is incorrect), the demand curve is not perfectly elastic (so C is incorrect), and there are strong barriers to entry (so D is incorrect).		 A
minimax A. A single firm in the industry. A
kimi A. A single firm in the industry. A
wenxinyiyan A

Explanation:
A monopoly is a market structure where there is a single firm in the industry that produces and sells a good or service without any close substitutes. This single firm has significant control over the market price and output.

Option B, "Price equal to marginal revenue," is not a characteristic of monopoly. In a monopoly, the price is typically set above the marginal revenue because the monopolist can control the market price.

Option C, "Perfectly elastic demand curve," describes a competitive market, not a monopoly. In a competitive market, firms are price takers, meaning they have to accept the market price, which leads to a perfectly elastic demand curve for each firm.

Option D, "Weak barriers to entry," is also not a characteristic of monopoly. In fact, monopolies often arise due to strong barriers to entry, such as high start-up costs, exclusive ownership of resources, or government regulations that restrict competition. These barriers prevent other firms from entering the market and competing with the monopolist.		 A
zhipu A. A single firm in the industry.

A monopoly is characterized by a single firm dominating the market, which gives it significant control over the price and supply of the product. This is in contrast to other market structures where multiple firms compete. The other options do not accurately describe a monopoly:
- B. In a monopoly, price is greater than marginal revenue, not equal.
- C. A monopoly faces a downward-sloping demand curve, not perfectly elastic.
- D. Monopolies typically have strong barriers to entry, not weak.		 A
gpto1 A A