Which countries are these famous places in? Which of the answers isn't right?

Places: ①Sentosa ②Niagara Falls ③Big Ben ④Sydney Opera House ⑤Washington D. C. ⑥the CN Tower. ⑦the Tower Bridge

Countries: a. Canada b. Australia c. Singapore d. Britain e. America

A、②-a ④-b ③-d

B、④-b ⑦-d ⑤-e

C、①-c ③-e ②-a

D、③-d ⑤-e ⑥-a