Elderly man walks for 6 days

A 73-year-old man, surnamed Yu, from Ruian, Zhejiang province, walked more than 100 km from Beijing to Tianjin in six days and five nights after he lost contact with his tourist group in the Forbidden City on Oct 13. Yu said that he tried to look for his group but failed in the crowded tourist spot. He also tried to ask for help from men "in uniforms", but the latter could not understand his dialect.

Where did the old man lost contact with his tourist goup?

A. In the Forbidden City

B. In the Summer Palace

C. In the Temple of Heaven