Inferences & Claims From Statistics Practice Test

A scientist runs an experiment on 40 seeds, randomly assigning 20 to a high-light condition and 20 to a low-light condition. After 2 weeks, high-light seeds have a higher germination rate. Which claim is best supported?

A nutrition blogger recruited 60 volunteers from their social media followers to test a new smoothie for 4 weeks. Participants chose whether to drink the smoothie daily or not; no random assignment was used. At the end, those who drank the smoothie reported an average weight change of $-1.8$ lb, and those who did not reported $-0.4$ lb. The blogger claims the smoothie causes weight loss for adults. Which statement is justified?