参考答案

正确答案：A
解析：参见第6段4-6行：Sensible calculation of real-world risks is a multidimensional math problem that sometimes seems entirely beyond us．While it may be true that we can never do exceptionally well．大意是：计算现实世界的风险是多领域的数学题，似乎完全超越我们的能力，并且我们永远也不能做得太好。