What does "these recommendations" refer to? Choose the words that complete the sentence.

We often think we know all the facts when it comes to
improving our health and preventing illness and disease. Most
physicians and nurses would probably advise exercise and a balanced diet. But research suggests that adding a few doses of laughter to these recommendations could also help you to
be healthier

1 : illness and disease
2 : exercise and a balanced diet
3 : all the facts
4 : most physicians and nurses