Given the question: Read the following article and select the best answer. Article: Boys and girls,as we all know,most people,especially young people ,tend to care about their hair much because hair plays a very important role in our appearance.But can you imagine what other uses hair has?Do you have any idea that human hair may become a new solar energy soutce?Before we begin with the new content of our Physics ,let me tell you a new invention first. It's reported that a Nepali teenager has designed a $32 solar panel using human hair. Milan Karki,who is 18 years old and lives in a village in rural Nepal,used human hair to replace silicon ,which is a common but expensive componet of solar panels. By using hair as a replacement,Karki says that solar panels can be produced for around $32,a price that could be halved if they were mass-produced. The solar panel works,because melanin ,which gives hair its colour,is light sensitive and can act as an elecrtical conductor.Kaiki was inspired to think of the idea by a Stephen Hawking book ,which explained how to create elecrtic energy from hair. The device that Karki has invented is capable of producing 9V or 18V of energy--plenty to charge a mobile phone. "Half a kilo of hair can be bought for only 16p in Nepal and lasts a few months;whereas a pack of batteries would cost50p and lasts few nights,"according to The Daily Mail. The solar panel is claimed to be easy to service as the hair is easy to replace. Karki has now seng out several devices to other disrticts near his home for tetimg .He said,"First I wanted to provide elecricity for my home,then my village .Now I am thinking for the whole worle." So next time when you have a haircut,do remember to keep your hair cut down to use for energy.Perhaps you can also provide elecrticity for your home,even your village using your own hair. Question: Which of the following is true about the new invention? - We can buy solar panel for around $32 using hair as a replacement in the market. - The device can produce 9V or 18V of energy. - Karki thought of the idea of inventing the device all by himself. - Kaiki provides elecrticity for his home using hair.
The answer is:
The device can produce 9V or 18V of energy.