A five-year-old child knows over six thousand words he or she has also learned more than one thousand rules of grammar.
选项：

A:A five-year-old child knows over six thousand words, he or she has also learned more than one thousand rules of grammar.;
B:A five-year-old child knows over six thousand words. He or she, has also learned more than one thousand rules of grammar. ;
C:A five-year-old child knows over six thousand words. He, or she has also learned more than one thousand rules of grammar.;
D:A five-year-old child knows over six thousand words, and he or she has also learned more than one thousand rules of grammar.