Which is the most effective way to combine sentences 1 and 2?
Alfred I ruled England for nearly 20 years, and he ruled from A.D. 871 to 899.
Alfred I ruled England for nearly 20 years, which were A.D. 871 to 899.
Alfred I ruled England for nearly 20 years, from A.D. 871 to 899.
Alfred I, who ruled England, did it from A.D. 871 to 899, nearly 20 years.