The correct selections are B and C because both define a function as a member of an object context, which is the essential JavaScript pattern for declaring a method. MDN defines a method as a function that is a property of an object. It also shows that a function expression can be assigned to a variable or property and then invoked later. In option B, Score: function() { ... } represents an object-literal method property. This pattern is commonly used when defining custom objects, prototypes, configuration objects, or class-like structures in JavaScript. In option C, this.Score = function() { ... } assigns a function to the current object instance, creating an instance method that can be called through that object. Option A does not declare a method; as written, it is only an invalid or incomplete variable assignment and does not use the function keyword or method syntax.
Option D invokes Score() and assigns its return value to a; it calls a function rather than declaring a method.
References/topics: JavaScript custom classes, object members, function expressions, object-literal methods, instance methods.