elegant way for an object composed of other objects to fail in c#

if you have an object that is composed of a bunch of other objects ie:

class A{
  B b {get;}
  C c {get;}
  private A(){
    b = B.Make();
    c = C.Make();
  }
}

And classes B and C are set up to return null when an exception is thrown, is there a better way than mass-checking for null in As members for null to have it fail as well?

Admittedly my understanding of exception management is poor, but it would make sense for B and C to not handle their own exceptions and instead let them bubble up to A, thereby circumventing the entire null fiasco. But what if they're classes with uses independent of A?