A. An easy to follow procedure
Marlena likes history and geography the best.
So 'who enjoys many different subjects' would be the answer.
Further explanation: The sentence will be the same whether that non restrictive modifier was present or not.
Answer: B. Make sure everyone participates.
In every group meeting, it is important to make sure that all members participate. This will allow a better exchange of ideas to take place. It will also ensure that the workload is divided among all members. This rule is likely to make group meetings more peaceful, fair and efficient.