I am trying to figure out which form to use to claim a loss on the sale of my dad's house. Turbotax leads me to form 4797, sale of business property, however I have been advised to use schedule D. Doe anyone know the correct answer?

More details are necessary. Did you sell the house AFTER it was transferred to your name or did you sell it as executor of his estate?

If afterwards, how long have you had it and are you sure there was a loss? On what basis do you think it's a loss?