An act, as simple as shaking hands when meeting new people is an example of: values. symbolic behavior. mores. social stratification.

This would be symbolic behavior. While the act itself doesn't have a meaning on its face, it does have a deeper meaning that only makes sense to those who are part of the culture and understand its salience. To those who are unaware of the culture or who haven't been part of it for long, the acts might seem strange or useless.