The correct answer is (d).
Option (a) is what people who design quizzes call a "distractor".
If you have no idea how to get the correct answer or if, for some reason, you might think that a
You will be distracted from the correct answer and select option (a).
You are absolutely correct: Without information on the rate and the concentrations, there is no way you can give a numerical value for the rate constant.
Teachers have ingenious ways to discover if you really understand a concept.