In the Middle Ages the vast majority of European cities had walls around them

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the following numbered blanks.
THE OLD GATE
${\,\,\,\,\,\,\,}$ In the Middle Ages the vast majority of European cities had walls around them. They (i) _______ to defend the city, but they also kept out undesirable people, like those with contagious diseases.

${\,\,\,\,\,\,\,}$ Most of London's gates had been (ii) _______ by the end of the eighteenth century. However, by a stroke of luck, the last of them was preserved. This gate is, in actual fact, not called a gate at all; its name is Temple Bar, and it marked the (iii) _______ between the old City of London and Westminster. However, as the (iv) ________ of traffic through London increased, Temple Bar became an obstacle to its free flow. In 1878 it was decided to take it down, so its stone were numbered, dismantled and put in storage. A couple of years later a wealthy businessman bought the stones and re-erected them at his house in Hertfordshire.

${\,\,\,\,\,\,\,}$ In the 1970s the Temple Bar Trust was (v) _______ with the intention of returning the gate to the City of London. Much of the money for this project was donations from the Temple Bar Trust. The stonework needed a lot of restoration, which was carried out by the Cathedral Works Organization. Today, Temple Bar stands next to St Paul's Cathedral.