Read the following article and answer the question. Article: Everyone needs safe drinking water, but about 1.1 billion people have no access to clean water. Most of the world's water is salty ocean water or frozen polar ice. By 2050, the world's population could grow from 6.7 billion to more than 9 billion. All of those people will need water to drink. But the bad news is that some areas of the world are growing drier because of climate change. The total area of the Earth's surface classified as very dry has doubled since the 1970s. Sadly, the precious resource is still misused in industry, in farming and at homes. Therefore, the world is facing a crisis over water. "You do the math, and it gets a little scary," says Stuart Minchin, a water expert in Australia. "We're waking up," he says. "But not fast enough." In southern Australia, farmers have been hit hard. They can't irrigate their fields well enough. The Australian government has launched a $1.3 billion project to improve Australia's irrigation system to stop the crop production dropping further. Australians have serious water worries, but it could be worse. They don't have to fear that when they turn on the tap, nothing will come out. That's the case in India. Many people in New Delhi, the capital, go without clean water for days. City leaders have taken stricter measures to save water. Users pay a very high but affordable price for it. Homeowners who waste water are given large fines. There are 1.9 million people who live in Las Vegas, Nevada. Now it has grown by more than 300,000 people since 2002. But it uses less water today than it did seven years ago. Question: Which of the following is NOT a reason for a water crisis? Answer:

Available choices:
(a). Climate change.;
(b). Water's becoming salty.;
(c). Population growth.;
(d). Water's being wasted.;
Answer:
(b).