[单选题]
How does the total mass of thkds )6u j9i3,k wrrli6igy *7ge products of a nuclear ilw0we l( 2; ls3yrb, /wr0gkjfission reaction compare to the mass of the ;gr s 0(bylwlewik3 wrl2j/0,original elements?
A. greater
B. less
C. the same
D. varies according to the reaction
