September 29th, 20 17, the world's first quantum secure communication trunk line-"()" was officially opened.

Hello, answer C. Analysis: The world's first quantum secure communication trunk line-"Beijing-Shanghai trunk line" was officially opened on the 29th. Combined with Mozi satellite, China scientists successfully realized the first intercontinental quantum secure communication with Austria in the world. This indicates that China has built a prototype of a wide-area quantum communication network integrating heaven and earth.

Excerpted from Xinhua News Agency's "China opens the world's first quantum communication trunk line and successfully realizes the first intercontinental quantum communication"