Final answer:
The method most commonly used to determine if an element is part of a collection in various programming languages is the contains() method.
Step-by-step explanation:
When determining if a specified element is a member of a collection in programming, the method commonly used is contains(). For example, in Java, the contains method is available for collection classes like List, Set, and others in the Java Collections Framework. If you are using a class or framework that does not provide a contains method, it would be necessary to implement the functionality to check for the presence of the element yourself, which could be similar to methods like isMember(), hasElement(), or checkElement(). However, among the options provided, contains() is widely recognized and used.