18. The political, social, cultural, or economic setting for an event or
idea in history.

written by alan ward and published in 2003. ward is a historian and was a professor at the university of connecticut.

if this isn't what you are looking i would like to know more details.

i am not 100   percent sure but i do know that hitler was burned to death with gas so that makes me think it is d. because they were under his control if they fail or not do as told they will be killed but i could be wrong hope this