Answer the following question: Even before there were people, there were cases of air pollution. There were dust storms. Volcanoes erupted, sending ash and poisonous gases into the atmosphere. When people appeared on the scene and began their conquest of nature, they also began to pollute the air. They cleared land, which made possible even larger dust storms. They built cities, and the soot from their hearths filled the air. The Roman author Seneca wrote in A.D. 61 of the "stink, soot and heavy air "of the imperial city. In 1257, the Queen of England was forced to move away from the city of Nottingham because the heavy smoke was unbearable. The industrial revolution brought even worse air pollution. Coal was burned to power factories and to heat homes. Soot, smoke, and sulfur dioxide fill the air. The good old days? Not in the factory towns. But there were large rural areas unaffected by air pollution. With increasing population, the entire world is becoming more urban. It is the huge cities that are most affected by air pollution. But rural areas are not unaffected. In the neighborhoods around smoky factories, there is evidence of increased rates of spontaneous abortion and of poor wool quality in sheep, decreased egg production and a high death rate in chickens. Traffic police in Tokyo have to wear gas masks and take "oxygen breaks" --breathing occasionally from tanks of oxygen. Smog in Athena at times has forced factory closings and traffic restrictions. Acid rain in Canada is caused by air pollution in the United States, contributing to strained relationships between the two countries. Sydney, Rome, Tehran, Ankara, Mexico City, and most other major cities in the world have had frightening experiences of air pollution. One of the two major types of smog--consisting of smoke, fog, sulfur dioxide, sulfuring acid (H2SO4), ash and soot--is called London smog. Indeed, the word smog is thought to have originated in England in 1905 as a contraction of the words "smoke" and "fog." Probably the worst case of smog in history started in London... It can be inferred that when writing this article, the author was in a(n) _ mood about the topic. A) sympathetic B) optimistic C) desperate D) concerned
Answer:
D