Tremaine is a self$-$employed accountant. What expense may be deducted directly on his Schedule C$?$

Half the amount of the self$-$employment taxes calculated on his Schedule SE$.$

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

The amount he contributes to his simplified employee pension $($SEP$).$

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