Bavarian Beer Music

What would fit in the blank?
Here is a passage about Oktoberfest. Which of the (a ~) (d) that fits in the blank? Y are the three other "inappropriate" Have you ever wondered about the origins of Oktoberfest, popular festival with German sausage and beer and music Bavarian traditional? It all began on October 12 in 1810, when Prince Ludwig of Bavaria married Princess Therese von Sachsen-Hildburghausen. On a whim, royalty Bavarian invites the citizens of Munich to attend the festivities of the wedding day, held in the field opposite the gates of the city. It was a resounding success, and well remembered fondly by all participants, who a year later decided to hold back. _________, The festival comes from year to year, which perpetuates itself until today. (A) Thus, (b) As (c) And so on (d) Instead
(A) So
Bavarian Beer Festival (part 3 of 4)