Use the scenario to answer the question.

The best question for George to ask in order to clarify what Jess has said is:

**"When you talked about the nutritional value of milk, were you talking about cows or goats?"**

### Explanation:
This question directly addresses George’s confusion regarding the subject of Jess's statement. Since Jess discussed both cow's milk and goat's milk, George needs to determine which specific type of milk Jess was referencing when she provided information about nutritional value. Asking this question would allow Jess to clarify her statements, and it also helps George avoid making an accusation about incorrect information without fully understanding the context of Jess's presentation.

The other options have limitations:
- **"Did you know that some of the information you gave about milk is incorrect?"** assumes that Jess is definitely incorrect without giving her a chance to clarify.
- **"If you meant cow’s milk earlier, where did you get that information?"** also assumes that Jess was referring to cow’s milk without allowing her to clarify her statement first.
- **"Can we look up the information you gave about milk to make sure it’s right?"** is a valid approach but does not directly clarify what specific information George questions; it also may not lead to a quick answer in the context of a presentation.

Thus, the second option is the most effective for clarifying the misunderstanding.