Sometimes, pregnant women are very emotional. this is believed to be caused by extra estrogen and progesterone that are released during pregnancy and would be considered an effect on behavior.

Activational effect is the correct answer.

Activational effect is an impermanent hormonal effect that leads to a change in physiological activity or behavior in both humans and adult animals. For instance, when testosterone levels rise in male songbirds they become more aggressive and tend to engage in courtship behavior. Also, a pregnant woman may get more emotional than usual due to an extra level of progesterone and estrogen during pregnancy.  

are there any answer choices

"d.) carbon dioxide and hydrogen sulfide"