What is true of the population shown in this graph?
a. the population is not changing much over time.
b. there are many factors at work to control the population.
c. the population is growing unchecked.
d. the population has increased until it reached its carrying capacity.

In a study, people were asked to imagine simple occasions that made them happy and to remember events that made them feel proud about themselves. it was observed that the subjects developed an increasingly positive attitude. these changes are known to be healthy, leading to greater physical activity and reducing unhealthy habits. based on this excerpt, we can conclude that a positive attitude .