Two circles that have / as a common internal tangent

I think it’s a and c hope I’m right

Ibelieve it's the pacific islands 

The zhou dynasty (1046-256 bce) was the longest-lasting of china's dynasties. it followed the shang dynasty (c. 1600-1046 bce) and it finished when the army of the state of qin captured the city of chengzhou in 256 bce.