What is the c key of the guitar score in Broad Sky?

The guitar score of "Broad Sky" is in the following key:

"Broad Sky" is a Cantonese song sung by China Hong Kong rock band Beyond, written and composed by Ka Kui Wong, and arranged by Beyond and Ryo Kunihiko. It was included in Beyond's Cantonese album "Joy and Fury" released by Warner Records on May 14th, 1993.

Creation background:

In p>1993, Ka Kui Wong composed the melody of the song and recorded a demo by playing and singing on the guitar. However, he thought that the song had no sense of strength, so after discussing with other members of the band, he decided that the piano was the main accompaniment of the song and named the demo Piano Song.

In May, Beyond returned to Hong Kong from Japan, which coincided with the 1th anniversary of Beyond's founding. So Ka Kui Wong wrote this song "Broad Sky" which recorded Beyond's ten-year mental journey with this demo called Piano Song. The lyrics carried the hardships of Ka Kui Wong and the band's development in Japan and their persistence in their ideals, and were included in the Cantonese album "Music and Anger". This song also expresses Ka Kui Wong's deep struggle and disappointment with the Hong Kong music scene.