Selecting answers to MCQ with number pad

Is there a way to have participants select their answers to a MCQ using the number pad? Right now, I have a 4-option questionnaire but participants must click on the correct answer. I'm replicating a study though so my response time won't line up if I'm not using the same method as the original study: what they did is participants needed to push number 1 to select the first answer, number 2 for second answer, etc. Not even sure if they were able to number the answers since they are supposed to be randomized.