Answer: Option (B) is the correct answer.
Step-by-step explanation:
The stair-step line in periodic table usually separates metals from non-metals. On the left side of this line metals are placed which are represented by pink squares in this case.
Whereas on the right side, non-metals are placed which are represented by yellow squares in this case.
Thus, we can conclude that the stair-step line between the pink squares and the yellow squares separates the metals (pink) from the non-metals (yellow).