Which statement is true when declaring the member variable count as static?

class my_class{
public: static int count;
};

• All objects that try to access their count member variable actually refer to the only class-bound static count variable.
• The variable is allocated only once, regardless of how many objects are instantiated, because it is bound to the class itself, not its instances.
• The variable existd when no objects of the class have been defined, so it can be modified at any point in the source code.
• The variable cannot be modified by any part of the code in the same application or thread. However, other threads may modify it.