You can conclude that Florida lacks in bedrock because sinkholes form where there is low amount of such.
Characters, A backround story
The correct answer is Sea of Japan - answer b) is the correct one!
This sea borders Japan, South and North Koreas, China and Russia.
This sea is named after Japan in most languages, not only in English.
South to it is the East China Sea, which separates China from Taiwan.
The removal of material by erosion will cause the crust to RISE