ANSWER
B. 5, H
Step-by-step explanation
A sample space is a set of all the possible outcomes of an experiment.
The possible outcomes for rolling a number cube are:

The possible outcomes for tossing a coin are:

Therefore, the only option that can be an element in the sample space for first rolling a number cube and then tossing a coin is option B.
This is because the number comes before the Head (or tail) unlike the other options:
