Answer: They will spend less on consumer goods like butter.
Step-by-step explanation:
In any economy, the amount of resources such as raw materials, money,etc available for production are limited. So, the country has to make a trade off between whether to spend more on military goods or on consumer goods. So, when the country decides to spend more on guns, then it will have less money and other resources to produce butter.
So according to the "Guns and Butter" example, if a country decides to spend more on military goods, then they will have less resources to spend on consumer goods like butter.