Answer:
The answer is C. "The metal to the left of phospherus in the same row"
Step-by-step explanation:
It says that phospherus has a higher atomic radius than the other unkown element. But it has different characteristics compared to phospherus. So that means that it would not be able to be in the same row because elements in the same row share the same charectoristics. And since we want its atomic radius to be lower than phospherus, it would have to be to the left of it because reading left to right all atomic numbers, mass, and radius gets higher
Please let me know if my reasoning was correct!! :)