Answer:
b. is a replication
Explanation:
Replication is the term given to repeating the same research study in different environment  and with changed subject. It is done to decide whether core finding of first study still holds true for other situation and context or not.
here impact of computer simulation helped chemistry students. Now jack  wants to see if simulation van help student in physics or not thus impact of simulation is being researched again and hence it is replication research methodology.