Question: What transit line serves the mall that has 12 million visitors a year?
Sentence (from "MRT Purple Line"): The MRT Purple line (Thai: รถไฟฟ้ามหานคร สายสีม่วง ), officially the MRT Chalong Ratchadham line (Thai: รถไฟฟ้ามหานคร สายฉลองรัชธรรม ), is a rapid transit line of Bangkok's Metropolitan Rapid Transit system for the Mass Rapid Transit Authority of Thailand (MRTA) in the Bangkok Metropolitan Region and Nonthaburi Province.
Relevant evidence: No