The correct answer is A. The king said that his force would protect the kingdom.
The king is the one who is speaking, so the pronoun “my” refers to him. The verb “will” indicates that the king is making a prediction about the future, and the noun “force” refers to his army. The king is saying that his army will protect the kingdom.
Option B is incorrect because it uses the pronoun “the king’s” instead of “my.” This suggests that the king is not the one speaking, but rather someone else who is talking about the king.
Option C is incorrect because it uses the verb “should” instead of “will.” This suggests that the king is giving an order, but not a prediction.
Option D is incorrect because it uses the verb “will be” instead of “will.” This suggests that the king is commanding his force to be protected, but not to protect the kingdom.