A. Mass extinction is the answer
People who have darker skin have more melanin which is a black or dark brown pigment in the skin. When we are out in the sun our skin produces more melanin, which helps our skin be more resistant in the sun. This is why we tan.
You could prevent it by not seeing it as much
A solution that has a pH of 6.8
it is <em>acidic</em><em> </em>as it has got ph value less than 7....But as it has got ph value near to 7 it is weak acidic..