An online company sold 3,586,598 copies of the book Favorite Pizza Recipes and 2,819,249 copies of the book Easy-to-Learn Guitar Songs.
Round each number to the nearest hundred thousand. 
About how many copies of the two books were sold altogether?
 A.
5,000,000
 B.
6,000,000
 C.
6,300,000
 D.
6,400,000