26. What is the main idea of the article? (A) Most commercially available yogurts are ineffective at improving health due to lack of live bacterial cultures. (B) Yogurt has recently been discovered to function as a complete immune system booster, replacing supplements. (C) Maria Branyas Morera’s exclusive diet of yogurt provides direct evidence that dairy can prevent age-related diseases. (D) The bacteria found in yogurt may play a role in extending human lifespan through their impact on gut and overall health.