Read the paragraph.
An engineer named Elijah McCoy invented the "oiling cup" which kept trains and steamboats oiled when they were moving. The use of the
oiling cup became known as the "McCoy system." When people say "It's the real McCoy," they mean it has what it takes to make something work
perfectly.
Which words best describe the author's purpose?
O 1. to inform
2. to persuade
O 3. to inspire
O 4. to entertain