The correct answer is: A. The client told his lawyer that he was going away for a few days and would call him when he got back.
The client’s statement is a simple declarative sentence, which means that it is a statement of fact. The client is not making a promise or an assurance, but is simply stating what he is going to do.
The other options are incorrect because they all imply that the client is making a promise or an assurance. Option B is incorrect because the client is not using the word “promise.” Option C is incorrect because the client is not using the word “will.” Option D is incorrect because the client is not using the word “definitely.”
In addition, option A is the most concise and direct option. The other options are all longer and more complex, which makes them less clear and concise.