Which statement is most clearly objective?
a. according to hernandez, i believe pilots must retire in their 60s.
b. walters argues that no american in society is truly an island.
c. the strongest aspect of cunningham's argument is the research.
d. when green discusses "reforms," she actually means profits.

Statement b is the most objective. This is because the rest of the statements are putting forward someone's opinion.
A is talking about what Hernandez says about you
C is an opinion regarding Cunnhingham's argument and may be debated
D is an interpretation of what Green means when she speaks of reforms
B is a statement of what Walter argues. This can be proven by facts and cannot be debated, as this is actually what Walter argues.