Suppose country oakland has $100$ cats, while country Midland has $110$ tvs$.$ They agree to trade $45$ cars for $55$ tv sets. Which assumption guarantees that the post trade consumption bundle increases utility for both?

Expectations of a future relationship between the two countries.

Scarcity of goods within a country.

Diminishing marginal utility from repeated consumption of the same good.

Uncertainty about quality of the other product.

Government policies ensure that the overall benefits are positive