Update prelimdataset.csv

prelimdataset.csv

@@ -136,7 +136,7 @@ Media28.mp4,"How often is a chicken packaged by the packaging helper?\n
 (A) Approximately every second\n
 (B) Once\n
 (C) Approximately every 2 to 3 seconds\n
-(D) Every 15 seconds",A
+(D) Every 15 seconds",C
 Media29.mp4,"How often did the machine release a package onto the conveyer belt?\n
 (A) 4 times\n
 (B) Approximately Every second\n