Final answer:
The example of Prime Minister George Grenville's use of the mercantile system is best described as implementing policies to promote economic self-sufficiency and maximize exports, in line with mercantilist principles.
Step-by-step explanation:
The economic policy known as mercantilism emphasized the accumulation of wealth through a favorable balance of trade, and it often involved stringent governmental controls to achieve this end. Prime Minister George Grenville's implementation of policies is an example of this mercantile system in action. The options provided for the student's question describe different economic approaches, but Grenville's policies are best represented by an increase in government control to maximize exports and reduce imports, reflecting mercantilist ideals.
Therefore, the answer to the question is option B) Implementing policies to promote economic self-sufficiency and maximize exports. This describes the essence of mercantilism, which sought to protect domestic industries, restrict imports through tariffs or outright bans, and promote the accumulation of precious metals, such as gold and silver, through a surplus in trade.