Interpret the coefficient on radio.

A $$1$ increase in spending on radio decreases revenue by $$19\mathrm{.}45$

A $$1$ increase in spending on radio decreases revenue by $$1945$

A $$1$ increase in spending on radio increases revenue by $$19\mathrm{.}45.$

A $$1$ increase in spending on radio increases revenue by $$1945$