C # garbage collector reference

Will the garbage collector be a free resource for a cross-referenced object / class that no longer references the main program. For instance -

class class1
{
    class2 m_RefClass2;
}
class class2
{
    class1 m_RefClass1;
}

class class3
{
    public class3()
    {
        class1 obj1 = new class1();
        class2 obj2 = new class2();
        obj1.m_RefClass2 = obj2;
        obj2.m_RefClass1 = obj1;
    }
}