I believe the answer is: c understanding constancy and change throughout the lifespan.
In social settings, developmental science research is being done by observing the change that the subjects experience if being put at a certain time of environment over time. Example of its research would be finding out whether there is a correlation between parents income with performance throughout school years.
A. increases.
I hope it’s right :P
Answer:
An optimistic person would be stable.
Explanation:
an optimistic person is always sure about his or her success.
