5446
San Ysidro Border Crossing Otay Mesa Border Crossing AMTRAK ( Pacific Surfliner ) Metrolink The Coaster San Diego and Arizona Eastern Railway San Diego Trolley  San Diego Metropolitan Transit System  Sprinter  San Diego  County contains three public state universities : University of California San Diego ; San Diego State University ; and California State University San Marcos .
 city of headquarters: San Diego Metropolitan Transit System, San Diego
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
 Entity Pairs:  San Diego Metropolitan Transit System, San Diego 
Answer:
 city of headquarters: San Diego Metropolitan Transit System, San Diego