Nil error on <% @people.each do |person| %>

Hi, I am trying to start off in my rails program with a select a person
from a drop down list
as in “<% @people.each do |person| %> .”
I get a “nil error” trying the drop down list, but in a regular list
program I get the list of people.I checked to model ad the controller
and they look the same as the list, except I am trying to create a drop
down list as opposed to a list/Thanks for any helpJim