5. Choose the sentences with the correct form of the Genitive Case of Nouns. 1. Hilbert's and Albert's brother is a doctor, 2. э, 3. Robert and Hilbert's brothers are doctors. 4. Hilbert's and Albert's brother are a doctors. 5. Hilbert and Albert's brother is doctor. A) 1,3,5 B) 2,4 C)2,3 D) 4,5 E) 1,3,4​