The word needed here is a noun referring to the large pieces of fabric that catch wind and move a sailboat forward. The correct spelling for this is "sails."
"Sales" refers to the act of selling goods and is a homophone of "sails," meaning it sounds the same but has a completely different meaning and spelling. "Sailes" is simply an incorrect spelling, it does not exist as a proper English word. "Sells" is the third person singular form of the verb "to sell," used for actions like "he sells cars," and it does not fit as a noun describing parts of a boat.
Since a boat's sails are the fabric sheets that catch the wind, "sails" is the correct word, making option 2 the answer.