Today, Malcolm moderated a group discussion. He could tell that all the participants were well prepared, because they all

skimmed over their texts while others were talking.
came up with their own opinions on the spot.
made a point of being heard no matter what.
had notes about important viewpoints and ideas.

To understand the answer to this question, we can look at the statements and analyze them one by one.

- Skimmed over their texts while others were talking: This statement suggests that the participants were well prepared because they were reviewing their texts or notes during the discussion. Skimming over the texts implies that they had already read or familiarized themselves with the material beforehand.

- Came up with their own opinions on the spot: This statement suggests that the participants were well prepared because they were able to provide their own opinions during the discussion, rather than just reiterating information from the texts. This indicates that they had a solid understanding of the topic and were able to think critically.

- Made a point of being heard no matter what: This statement suggests that the participants were actively engaged in the discussion and were assertive in expressing their viewpoints. This behavior can indicate that they were well prepared and confident in their knowledge, as they wanted to contribute to the conversation.

- Had notes about important viewpoints and ideas: This statement suggests that the participants were well prepared because they had taken the time to make notes about important viewpoints and ideas. This indicates that they had a systematic approach to the discussion and were organized in their thinking.

Based on these statements, we can conclude that all the participants were well prepared because they actively engaged in the discussion by skimming over their texts, coming up with their own opinions on the spot, making their voices heard, and having notes about important viewpoints and ideas.