Answer: the right answer is a) the right to occupy their land
Explanation: back then, it was extremely important to own lands because it means you had power. Especially for the monarchy that needed to own many lands to expand their power geographically. So, a simple way to get more lands without paying anything was to allow their colonies a degree of independence. That way, the colonies had the illusion of more freedom (still being a colony) and the monarchy could have more lands.
I hope this helped :)