Which of the following pairs has both members from the same period of the periodic table?

Q. Which of the following pairs has both members from the same period of the periodic table?
A. Na – Ca
B. Na – Cl
C. Ca – Cl
D. Cl – Br
Answer: Na – Cl

A. Na – Ca
B. Na – Cl
C. Ca – Cl
D. Cl – Br
Answer: Na – Cl