Answer:
For this case the correct answer is the product
Explanation:
When we have two events that occur at the same time, let's assume A and B the two events, and we want to find this probability:
And we want that he probability of each occurrence yielding the same result is the of the probability of each separate event since "The probability of two independent events occurring together is the of the probability of each event occurring separately". So for this case we need to use the independence condition like this:
And then the correct option is product rule.