Что нужно вставить в эти предложения -- who, which, whose или that? The rooms [...] walls are yellow is the best in the

1. The rooms which walls are yellow is the best in the house. 2. The plant which flowers are red is a rose. 3. The dog who is playing with a ball is Chase. 4. This is the car that Tom bought. 5. That is the man whose car has been stolen.  6. I don\'t know which library to choose.