Chandra Is an Invalid And,therefore,she Cannot Put Her Signature on Her

Multiple Choice

Chandra is an invalid and,therefore,she cannot put her signature on her will.Her friend Nina signs the will for her.When Nina signs on behalf of Chandra,there is no one else in the house.Is the will valid?

A) Yes,since Chandra was present during the time the will was signed.
B) No,since she did not date it.
C) Yes,since she is presumed to be mentally competent.
D) No,since there were no witnesses present during the signing of the will.