A real estate developer in Florida, desiring to protect his high-rise apartment building o

n the beach from hurricane damage, has planted sea oats in two rows in front of his building in order to encourage the development of sand dunes between the water and his building. Which of the following, if true, casts the most doubt on the probable effectiveness of the developer's plan？

A．Sand dunes provide little protection for tall buildings against the wind, which is sufficiently powerful even in minor hurricanes to cause serious damage to buildings.

B．Sand dunes have been shown to provide effective protection against the storm surge, the pounding waves driven by hurricane-force winds onto dry land.

C．Although sea oats will lead to the growth of sand dunes over many years, it would be far faster to build concrete bunkers between the building and the water.

D．Hurricane insurance has become so expensive that many owners of beachfront property choose not to buy it.

E．The developer has invested in reinforced steel girders and shatterproof glass as a way of minimizing damage to his building in the event that a hurricane hits the area.