Answer:
Lithium
Step-by-step explanation:
As you go from left to right the atomic radius decreases.
As you go from top to bottom the atomic radius.
A. Carbon is farther right in the 2nd period.
B. Lithium is the first one in the 2nd period!
C. Neon is the farthest one on the right in the 2nd period.
D. Potassium is not even in the 2nd period