8) Select the sentence with the correct punctuation (commas, semicolons, colons, and quotation marks.)

Boxer's motto is this I will work harder!

Boxer's motto is this: "I will work harder!"

Boxer's motto is this, "I will work harder!"

Boxer's motto is this "I will work harder!"

Boxer's motto is this: I will work harder!

Boxer's motto is this: "I will work harder!"