在《新概念英语第三册》Unit1 Lesson17“The longest suspension bridge in the world”的课后习题（Multiple choice questions）中，有这样一道题目：

6. The length of the bridge is _________ the shape of the earth.

(a) so that    (b) such that    (c) that which    (d) thus

参考答案给的是B，个人觉得这个句子存在问题，想请问一下有人可以对本题/本句做出合理的解释吗？

附：原文

Verrazano, an Italian about whom little is known, sailed into New YorkHarbour in 1524 and named it Angoulême. He described it as ‘a very agreeable situation located within two small hills in the midst of which flowed a great river’. Though Verrazano is by no means considered to be a great explorer, his name will probably remain immortal, for on November 21st, 1964, the longest suspension bridge in the world was named after him.

The VerrazanoBridge, which was designed by Othmar Ammann, joins Brooklyn to Staten Island. It has a span of 4, 260 feet. The bridge is so long that the shape of the earth had to be taken into account by its designer. Two great towers support four huge cables. The towers are built on immense underwater platforms made of steel and concrete. The platforms extend to a depth of over 100 feet under the sea. These alone took sixteen months to build. Above the surface of the water, the towers rise to a height of nearly 700 feet. They support the cables from which the bridge has been suspended. Each of the four cables contains 26, 108 lengths of wire. It has been estimated that if the bridge were packed with cars, it would still only be carrying a third of its total capacity. However, size and strength are not the only important things about this bridge. Despite its immensity, it is both simple and elegant, fulfilling its designer's dream to create ‘an enormous object drawn as faintly as possible’.

参考译文：

1524年，一位鲜为人知的意大利人维拉萨诺驾船驶进纽约港，并将该港命名为安古拉姆。他对该港作了这样的描述：“地理位置十分适宜，位于两座小山的中间，一条大河从中间流过”。虽然维拉萨诺绝对算不上一个伟大的探险家，但他的名字将流芳百世，因为1964年11月21日建成的一座世界上最长的吊桥是以他的名字命名的。

维拉萨诺大桥由奥斯马·阿曼设计，连结着布鲁克林与斯塔顿岛，桥长4,260英尺。由于桥身太长，设计者不得不考虑了地表的形状。两座巨塔支撑着4根粗大的钢缆。塔身建在巨大的水下钢筋混凝土平台上。平台深入海底100英尺。仅这两座塔就花了16个月才建成。塔身高出水面将近700英尺。高塔支撑着钢缆，而钢缆又悬吊着大桥。4根钢缆中的每根由26,108股钢绳组成。据估计，若桥上摆满了汽车，也只不过是桥的总承载力的1／3。然而，这座桥的重要特点不仅是它的规模与强度。尽管此桥很大，但它的结构简单，造型优美，实现了设计者企图创造一个“尽量用细线条勾画出一个庞然大物”的梦想。