In uml behavioral modeling, a message is (points : 6) a named location in memory where information is deposited and retrieved
a data structure to hold information
a function or procedure call from one object to another object
a relationship between two objects

a function or procedure call from one object to another object

Explanation: UML(Unified Modeling language) behavioral modeling is the depiction of the relation of the elements in a dynamic manner and the dependency on time .Message in the UML behavioral modeling is a functional call taking place from one element to another.

The interaction is the model is seen through the flow of messages.Other options are incorrect because message is not information holding data structure, does not display the relation between object rather presents the flow and is not a memory location .