By definition altruistic behaviors a incur a cost to the rec

By definition, altruistic behaviors
   a. incur a cost to the recipient.
   b. incur a cost to the actor.
   c. result in a benefit to the actor.
   d. are beneficial to the recipient and the actor.

Solution

Answer:

b. incur a cost to the actor.

Altruistic behavior, a social evolution, the fitness of the actor decreases, whereas increase in fitness of the other individuals are observed.