Identify the memory location of data in this C# code

Here is definition of a class C:

class C {
   // inner struct S
  struct S {        
    public byte mb;         
  }
  public void Foo() {   
    S s1; 
    S s2 = new S();
    s1.mb = s2.mb = 20; // initialize s1, s2

    // a List of S initialized with s1,s2
    var ls = new List<S> { s1, s2 };
  }
  private int mi = 10; // A member of C
}

Suppose we create an instance of C and invoke C.Foo:

C c = new C();
c.Foo();

The data instances in above code namely - c.mi, s1, s2, ls[0], ls[1] - are allocated on either stack or managed heap at run-time. The ls[0] and ls[1] here refer to the items in list ls at index 0 and 1 respectively. Note that as items in list ls are of value-type, writing ls[0] (or ls[1]) in C# code would result in creating a temporary immutable copy of original item; but that is not our intention here.

Select all those statements below that are entirely true about the memory location of above data instances: