The policy of mercantilism entails all of the following except that:

Colonies exist for the benefit of the mother country.
Colonies should act as a source of raw materials for the mother country.
Colonies should act as markets for the mother country.
Colonies should develop manufacturing to export products to the mother country.
Trade would increase overall wealth.

In general, colonies were NOT meant to develope manufacturing and exporting to the mother country.

Colonies should develop manufacturing to export products to the mother country

The correct answer is:

Colonies should develop manufacturing to export products to the mother country.

To confirm that the answer is "Colonies should develop manufacturing to export products to the mother country," we can consider the principles and objectives of mercantilism. Mercantilism was an economic system practiced by European countries during the 16th to 18th centuries, with the aim of maximizing the wealth and power of the mother country. Here's how you can explain finding the answer:

1. Understand the principles of mercantilism: Mercantilism emphasized the accumulation of wealth for the mother country through maximizing exports and minimizing imports. The main goal was to maintain a positive trade balance, where exports exceeded imports.

2. Consider the role of colonies: In the context of mercantilism, colonies were seen as economic resources that existed primarily to benefit the mother country. They were intended to provide raw materials and resources that were in demand in the home country.

3. Analyze the options: Let's examine the given options in light of the principles mentioned above:

a. "Colonies exist for the benefit of the mother country" - This statement aligns with the principles of mercantilism, as colonies were indeed intended to benefit the mother country.

b. "Colonies should act as a source of raw materials for the mother country" - This statement is in line with the principle of obtaining resources from colonies for the benefit of the mother country.

c. "Colonies should act as markets for the mother country" - This statement is also consistent with mercantilism, as colonies were expected to serve as captive markets for the goods produced in the mother country.

d. "Colonies should develop manufacturing to export products to the mother country" - This statement contradicts the principles of mercantilism. The focus of mercantilism was on the mother country exporting goods to colonies, not the other way around.

e. "Trade would increase overall wealth" - This statement aligns with mercantilism as the accumulation of wealth through a positive trade balance was one of its main objectives.

4. Identify the exception: After considering all the given options, we can conclude that the exception to the policy of mercantilism is the statement "Colonies should develop manufacturing to export products to the mother country." This statement goes against the main objective of mercantilism by suggesting that colonies should develop manufacturing capacities to export products to the mother country, rather than mainly serving as providers of raw materials and markets.

Therefore, the correct answer is "Colonies should develop manufacturing to export products to the mother country."