Read the excerpt from "Isaac and Casey."

"Higher!” said Isaac. Casey jumped higher still. His back feet were at least four feet off the ground. It was miraculous!

Suddenly, a thought struck Isaac like lightning. He said the command one more time. "Higher!”

What is the meaning of the simile in this excerpt?

Just as Casey began to jump off the ground, lightning began to strike.
Just as Isaac began to realize something, lightning began to strike.
Much like lightning strikes, the idea struck Isaac suddenly and abruptly.
Much like lightning hurts when it strikes, Isaac’s realization hurt him.