All William's purposes were to be carried out, as far as possible, under cover of strict adherence to the law of the land of which he had become the lawful ruler. He had sworn at his crowning to keep the laws of the land, and to rule his kingdom as well as any king that had gone before him. And assuredly he meant to keep his oath. William was ________about the law.

squeamish

confused

contemptuous

conscientious

The word "conscientious" meant the intention to do rightful things, the want and desire to do things in a correct and lawful way. This personality trait is related to a person's conscience and the want to make the right decisions and actions.

In the given passage, the Norman duke William the Conqueror is described and how he wanted to maintain "the law of the land." He wanted "to keep the laws of the land and to rule his kingdom as well as any king that had gone before him. And assuredly he meant to keep his oath." And by that, he wants to justly and rightly rule the kingdom of England. And the "strict adherence" suggests the new king's conscientious attitude about the law.

Thus, the correct answer is conscientious.