[单选题]
The energy gap betwe76xssjl 8.cd g6qgg 4ien the valw- iq8 bwubjcj7) ah9.ence and conduction bands in a certain semiconductor is 1.27 i)bwha-w cb9juq 8j.5 eV. What is the threshold wavelength for optical absorption in this substance?
A. $599 \; nm$
B. $959 \; nm$
C. $873 \; nm$
D. $995 \; nm$