One Argument Favoring Free Trade Is That It Allows Markets

One argument favoring free trade is that it allows markets to expand and more goods and services to be sold than would be the case with restricted trade. This is considered an advantage of free trade because:

A) expanded markets allow sellers to specialize and use resources more efficiently.
B) with a given number of sellers in a market, market growth allows them to increase their monopoly power.
C) expanded markets allow sellers to raise their prices, even if some buyers leave the markets when the prices rise.
D) all of the above.