What is the proper way to punctuate this sentence? Colon, em dash, or comma?
Eating at a homeless shelter since March has provided me with a look into the thoughts of other people: both the homeless themselves and their friends.
Eating at a homeless shelter since March has provided me with a look into the thoughts of other people — both the homeless themselves and their friends.
Eating at a homeless shelter since March has provided me with a look into the thoughts of other people, both the homeless themselves and their friends.
Also, is there supposed to be a comma between "themselves" and "and"?