Select the correct answer.
Read the passage.

One day, Percy Spencer walked by a magnetron with a candy bar in his pocket, and it melted. It was the late 1940's and soon after, in 1947, a new kitchen appliance was created. They were large and expensive, but with the main advantage of speed. This invention has shaped how people cook and warm food even today.

What is the author describing?

A.
The way microwaves have changed since it was invented.
B.
The original size and cost of the original microwave.
C.
The process in which a candy bar can be melted by a microwave.
D.
How Percy Spencer accidentally invented the microwave.