Chuck purchased a van for $24,000 to use exclusively in his plumbing business. He sold it four months later in the same year for $18,000. What is the amount of gain or loss, and where on Form 4797 does Chuck report the sale?

$6,000 gain; Part I.

$6,000 gain; Part II.

$6,000 loss; Part II.

$6,000 loss; Part III.