Determining the Costs of Helping Has the Following Effect on Altruistic

Determining the costs of helping has the following effect on altruistic behaviour:

A) people are motivated to help for reasons that exclude the costs of helping.
B) the costs of helping can both increase or decrease the probability of helping, depending on the seriousness of the emergency.
C) higher costs increase the actual probability of helping behaviours.
D) higher costs reduce the actual probability of helping behaviours.