Popcorn Reading Comprehension

Which one of the following is not true?
Popcorns were discovered by the native Americans thousands of years ago in Guatemala or Mexico.though they were popped in China Sumatra and India long before Columbus reached America. It is known as Popcorn and also �popping corn� because it is a special variety of corn also known as Zea mays everta. It expands because the water expands on it when heated.

Popcorns were not only used as food but also as decoration for ceremonial headdresses and as ornaments on statues of their Gods. It is a hearsay or an unproven theory that an Indian named Quadequina first popped the popcorn in a dear skinned bag filled with sand for the thanksgiving feast.
But today the popcorns are popped in the highly technological machines and you buy them at movies and fairs. Street vendors also sell them by making them through the steam of gas powered poppers in parks and exhibitions.