The correct answer is: B. tense, restless.
The word “usually” indicates that the person is normally calm and relaxed, but today they are acting in a different way. The word “rather” indicates that the difference is significant. The words “tense” and “restless” suggest that the person is feeling anxious or agitated. These words are the best fit for the context of the question.
The other options are not as good fits for the context. The word “strict” suggests that the person is being demanding or severe. This does not seem to be the case, as the person is normally calm and relaxed. The word “unwell” suggests that the person is sick or injured. This is also not the case, as the person is normally calm and relaxed. The word “quiet” suggests that the person is not speaking much. This is not necessarily the case, as the person could be feeling anxious or agitated and still be quiet. The word “happy” suggests that the person is feeling cheerful or content. This is not the case, as the person is normally calm and relaxed but today they are acting in a different way. The word “humorous” suggests that the person is funny or amusing. This is not the case, as the person is normally calm and relaxed but today they are acting in a different way.