You Are About to Greet Paul for the First Time

You are about to greet Paul for the first time.Upon meeting him,you take his right hand and put it up to your forehead.You then put Paul's hand down and release it.In your culture,this is the custom for greeting people for the first time.Suppose that researchers have decided that this custom is really a functional universal.Which of the following would you assume to be the case in other cultures?

A) The custom is not used as much in other cultures.
B) The custom does not exist in other cultures.
C) The custom is triggered by different causes in other cultures.
D) The custom solves different problems in other cultures.
E) The custom has no equivalents in other cultures.