It started out innocently enough. It's still hard to believe. A baseball card was at the middle of our whole summer fiasco. Trent got me started with baseball cards. I followed baseball. This was different. He went crazy for this card of a pitcher I thought was lousy. He went on to tell me that the card I had was different. The baseball card company only made a few of these cards, and the people that made the card messed up the facts on this particular card. They printed someone else's statistics on the back. They only made 100 of them. Those cards were worth thousands of dollars. My mind tried to imagine what I would do with thousands of dollars.
Then, it happened. Word got around school, and everyone wanted to see it. I must have shown it to 100 people. Then, when I went to my locker at the end of the day, it was gone. Someone had stolen it.

"They only made 100 of them. Those cards were worth thousands of dollars"

What is the best way to combine these simple sentences into one compound
sentence?

A. They only made 100 of them, and those cards were worth thousands of dollars.
B. They only made 100 of them those cards were worth thousands of dollars.
C. They only made 100 of them worth thousands of dollars.
D. They only made 100 of them and those cards were worth thousands of dollars.