Some research has found that participants showed a greater willingness to suffer longer for a close relative than for:
a. a distant relative. This finding is consistent with kin selection.
b. the bystander effect.
c. pluralistic ignorance.
d. the negative-state relief model.

a. a distant relative. This finding is consistent with kin selection.  

Explanation:

Some research has found that participants showed a greater willingness to suffer longer for a close relative than for a distant relative. This finding is consistent with kin selection. Kin selection is the strategy whereby an individual favors the success of his close kin even at the cost of his/her own life, he/she is willing to inconvenience him/herself so that a close kin can thrive.

1) d

2)c

3)b

4) a

5)c

6) c