The author could strengthen his argument about how ear buds are dangerous when used in a car in the follolwing way:
D) by adding some statistics from accident reports that involved ear buds.
Explanation:
Statistics are about facts. Therefore, if they are added to an argument, it becomes much stronger and also a lot more tangible, since it makes it clear that what is being said is not a mere opinion and does not boil down to one's subjectivity and biases. If statistics from accident reports that involved ear buds are shown, it becomes clear it is truly dangerous to use ear buds in a car, that is, it shows accidents like that might actually happen.
