When Does the Consideration of Rewards and Costs Influence Whether

When does the consideration of rewards and costs influence whether or not an individual decides to help?

A) when people have the time to make a careful deliberate decision about whether to help
B) when people are faced with emergency situations in which they must make a quick decision about whether to help
C) when people are deciding about whether or not they should help a stranger
D) when people are deciding about whether or not they should help