题目内容：
请根据以下内容回答题：The Old Gate
In the Middle Ages the vast majority of European cities had walls around them. This was partly for defensive 51 but another factor was the need to keep out anyone regarded as undesirable, like people with contagious 52 . The Old City of London gates were all 53 by the end of the 18th century. The last of London's gates was removed a century ago, but by a 54 of luck, it was never destroyed.
This gate is, in 55 fact, not called a gate at all; its name is Temple Bar, and it marked the 56 between the Old City of London and Westminster. In 1878 the Council of London took the Bar down, numbered the stones and put the gate in 57 because its design was 58 it was expensive to 59 and it was blocking the traffic.
The Temple Bar Trust was 60 in the 1970's with the intention of returning the gate home. The aim of the trust is the 61 of the nation's architectural heritage.
Transporting the gate will mean physically pulling it 62 , stone by stone, removing and rebuilding it near St Paul's Cathedral. Most of the facade of the gate will probably be 63 , though there is a good 64 that the basic structure will be sound. The hardest 65 of all, however, will be to recreate the statues of the monarchs that once stood on top of the gate.
A．grounds
B．reasons
C．causes
D．purposes
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