Question

Which is a result of the release of stress hormones?

heart rate drops
body emits pheromones <---
sense of smell heightens
muscles tense

I'm not as sure about this one...
@jim_thompson5910

Answer 1

I'm not sure either, but I'll try to see what I can find

Answer 2

this may confirm the answer

http://sitemaker.umich.edu/ling111ec/pheromones

`"Pheromones are chemicals released by living organisms that send information to other organisms of the same species via scent. These pheromones are released in response to stress, alarm, danger, and sexual fertility. They are released by both insects and mammals in many situations."`