1. Since C alone had share in the proeprty and not her husband.
2. Now if C died beofre then on her death her husband will get the proeprty and then he could give thi to person of his choice.So if the Will is executed after death of C then it is valid.
3.Now if D was legally adopted then on death of C inherits the proeprty by law of succession even if there is no Will.