Read the following passage written by a teen hero:
i want to be a vocal advocate for nature.
i reject the idea that i am too young to make a difference.
i recently a group with a river cleanup.
i was mortified to see the destruction of animals and plants.
when i got home, i composed a letter to my state politicians and asked them to allocate more money to the local river cleanup effort.
i believe my vocation is to citizens see that we are at a junction.
we can decide to subject nature to abuse, or we can decide to be a benefactor to nature.
i won't let obstacles detract from my mission.

in sentence 4, the root in the word "mortified" means (5 points)

frustration

death

disappointment

sadness