Taking Food From Strangers

What's your opinion? If it's free and it looks edible, what would you do?
Push 1 for: Absolutely I would eat it.
Push 2 for: No, it's got rat poison.
Push 3 for: Inspect it thoroughly and weigh your options.

Today, a regular patron at the library brought me half of a sandwich. We had talked earlier about a delicatessen (notice I did not shorten this term to "deli") I had never frequented. She was adamant that I sample the menu from Viafore's, and I told her I was planning on going someday, but limited by public transportation.
Remembering this fact, she called me this morning at the library and said she would bring me a sandwich. I told her, "You really don't have to do this. It will make the other employees jealous." She quickly came up with a solution: "I'll just drop it by and say it's from your mom." Which is exactly what she did.
She's a nice person and not exactly a stranger...but accepting food from someone who've you only interacted with in several two- or three-minute encounters...is a bit questionable.
So what did I do?

I saved it for dinner and polished it off within a matter of minutes. No inspection. Just ate the durn thing.
I am a very trusting person.
You can take advantage of me easily.
If I had been poisoned by a crazy woman, or maybe it's one of those slow-acting poisons, I want my tombstone to read:

"Possessed a hunger for life and sandwiches."