Where did Columbus first set foot on the New Continent

A．Watling Island.

B．At the spot where a carved stone was erected to mark the event.

C．Somewhere in eastern Bahamas.

D．No consensus has been reached on the event among historians.

企业处置一项以公允价值模式计量的投资性房地产，实际收到的金额为100万元，投资性房地产的账面余额为80万元。其中成本为70万元，公允价值变动为10万元。该项投资性房地产是由自用房地产转换的，转换日公允价值大于账面价值的差额为10万元。假设不考虑相关税费，处置该项投资性房地产的净收益为( )万元。

A．30

B．20

C．40

D．10