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. Albert and Robert's brother are doctors. 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​