重点句型运用 — 英语选择题

根据提示选择正确的句子：以前公园里没有树，现在有一些。A. There were no trees in the park before, but now there are some. B. There was no trees in the park before, but now there is some. C. There are no trees in the park before, but now there were some. D. There is no trees in the park before, but now there was some.