An example of a resilient person would be 1) an intelligent person failing an exam. 2) a person with a disability going undiagnosed. 3) a low-income student graduating from college. 4)a fit person completing a marathon.

3) A low income student graduating from college.

Explanation:

Resilience is a term that is used to describe a person that finds a way to overcome adversity.  Resilient people are strong and resourceful.  In the examples given, numbers 1 and 4 do not present cases of people overcoming a difficult situation.  Example 2 is quite vague and would not necessarily constitute and example of resilience.  We would have to know more about the type of disability in order to make a better assessment.  But in example 3 we have the case of a student that has a difficult life situation but has managed to overcome the obstacles and graduate college, which is a great achievement.