I’m old and small and these strangers scare me

DEAR ABBY: I am a 91-year-old woman who is four feet tall who still drives a car and goes alone to shop and do business.

Jeanne Phillips (Dear Abby)My problem is that I am often approached by strangers who want to “help” me. This scares me because I can’t defend myself.

While someone who holds a door open for me is appreciated, I can’t tell who is a wallet thief who intends to take me down.

How can I communicate that I am able to take care of myself without offending the person?