Answer:
This is an example of a. social loafing.
Step-by-step explanation:
Social loafing is a term used in social psychology to describe a phenomenon that takes place when individuals working is group exert less effort than they would if working on their own. Groups are, sometimes, less efficient and less productive because of this phenomenon. Some people tend to think their effort is not necessary since others will be working hard. They do not feel responsible for how productive their actions will be any longer. That is precisely the case with Tom. The reason why he does not contribute is because he is certain that the others can handle it all by themselves.