C#: Clarifying child class field type?

Question

OOP

The problem is this: there is an abstract class A, its heirs: A1, A2, A3.
Abstract class B, its successors B1, B2, B3. Class B has a field of type A:
public abstract class B
{
public A field;
}
Is it possible to organize everything in such a way that in the child classes (B1, B2, B3), this field has the corresponding child type (A1, A2, A3)?
Hiding with new is not suitable, because you need the ability to access them through the base class (B).

Answer 1

stackoverflow.com/questions/5709034/does-c-sharp-s...
virtual (and\or generic) properties
Suitable or not - you know better.