How do you tip a door man for hailing you a cab?

If you're talking about tipping a doorman in a building you live in, you don't tip his for hailing a cab, that's part of his job. Instead, you give each of the doormen in your building a tip at Christmas holiday time. A friend of mine is a doorman and he says the building mgt. sends around a note near the end of the year with suggested amounts for each person (doormen, elevator men, etc.)

A dollar is the right amount. The doorman did not do enough work to earn more than a dollar. Other amounts take more time and thought. A dollar is easy to give without thinking about it.

I think it's B.