By referring to the period at the end of the sentence (lines 16-18), the author intends to point up the atom' s A: density B: mystery C: velocity D: consistency E: minuteness

By referring to the period at the end of the sentence (lines 16-18), the author intends to point up the atom' s A: (A) density B: (B) mystery C: (C) velocity D: (D) consistency E: (E) minuteness