Tommy is a self-employed accountant who operates his business out of a free-standing office building that he owns. Which of the following may he deduct on his Schedule C?

The cost of health insurance premiums for a plan Tommy purchased through the Marketplace.

Half the amount of the self-employment taxes reported on Tommy's Schedule SE.

The cost of purchasing paper and ink cartridges for his business printer.

The cost of knocking out a back wall and adding a client waiting area to his office building.