Please answer the following question: Read the article and select the best answer. Article: The main cause of a heart attack is not exercise or stress -- it's air pollution, according to a study published in The Lancetthis month. Researchers found spending time in traffic, whether as a driver or a pedestrian , tops the list of risk factors that bring on a heart attack. Jon Ayres, professor of environmental and respiratory medicine at the University of Birmingham, says, "Air pollution is not only linked to strokes, heart attacks and cancer -- it has a deep effect on those with existing respiratory conditions." So how can you avoid the damage? We asked the experts for their tips. TAKE TO THE SIDE STREETS Avoid main roads. These have the highest number of vehicles and also more traffic jams, which tend to run on diesel . Diesel engines emit tiny particles that reach the lungs most easily. Choose side streets, pavements, parks and avenues lined with trees. BUY SOME HOUSEPLANTS We spend 90 percent of our time inside, but studies by the U.S. Environmental Protection Agency have found that pollution levels can be two to five times higher indoors than outside. Objects such as synthetic carpets, TV screens can emit chemicals called volatile organic compounds (VOC,), which have been linked to diseases such as cancer. Researchers at Curtin University in Perth, Australia, found an increase in asthma risk among children under three who had high VOC levels in their homes. Therefore, the application of air fresheners and houseplants can keep the circulation of the air and absorb the pollutants. Question: What is the passage mainly about? Options: A: Tips to avoid the damage of air pollution. B: Air pollution is the main cause of a heart attack. C: Air pollution is linked to strokes, heart attacks and cancer. D: Pollution levels can be two to five times higher indoors than outside.
A:
A