Consider the following statements: 1) All machines consume energy. 2) Electricity provides energy. 3) Electrically operated machines are cheap to maintain. 4) Electrically operated machines do not cause pollution. Which one of the following inferences can be drawn from the above statements?

Explanation:

Statement 1: "All machines consume energy." This is a general statement about machines. Statement 2: "Electricity provides energy." This states electricity is a source of energy. Statement 3: "Electrically operated machines are cheap to maintain." This highlights a benefit of electrically operated machines. Statement 4: "Electrically operated machines do not cause pollution." This highlights another benefit of electrically operated machines.

Analyzing the options:

A) All machines are run by electric energy. This cannot be inferred. Statement 1 says all machines consume energy, but it doesn't specify only electric energy. There are other forms of energy (e.g., fuel, manual).

B) There is no form of energy other than electricity. This is false and cannot be inferred. Statement 2 says electricity provides energy, but it doesn't exclude other forms of energy.

C) Most machines are operated on electric energy. The statements do not provide any information about the proportion or prevalence of electrically operated machines compared to other types. We cannot infer "most."

D) Electrically operated machines are preferable to use. This is the most logical inference. Statements 3 and 4 list significant advantages of electrically operated machines: they are cheap to maintain and do not cause pollution. These two positive attributes make them desirable or "preferable to use" compared to alternatives that might be expensive to maintain or cause pollution.