Hydrogen and Lithium React Very Differently,although They Are Both Members

Multiple Choice

Hydrogen and lithium react very differently,although they are both members of Group 1.What is the primary reason for this difference?

A) The metallic character increases going down a group.
B) The ionization energy increases going down a group.
C) Electron affinity increases going down a group.
D) Electronegativity increases going down a group.
E) There is a very large difference in the atomic radii of H and Li.