You need to step things up. Only a couple of you did remotely well on the open book, 24 hour, take home exam.
You had a full day, with an open book, to answer 20 questions. There are no excuses for not making a high A on this thing.
Here are hints about how you can do better in the future.
1-Answer every question. If you see 20 questions on the test, send 20 answers back.
2-Read the material. These are open book questions because I have no idea if you are going to cheat, so I make the issue moot. But allowing you to look at the book means that you will be expected to get things right. Reading the material ahead of time helps.
3-Answer the question I ask, not the question you want to answer. If the question asks you to elaborate on a subject, elaborate on that subject. That means that I want you to explain it. Demonstrate to me that you can do more than repeat what is in the textbook.
4-Be lengthy. Fully answer the question without degenerating into pure bs. A brief incomplete answer gets a tiny grade, a lengthy one gets a higher grade.
You should also ask yourself if you have the discipline to take classes without supervision. It is no sin to need the structure of a lecture class. I tend to prefer them.
Please don't waste my time, or your money if you don't intend on giving this class the time necessary to succeed. I get paid the same whether you pass or fail.