Amixed choir of men and women sing a melody line. the men sing one octave lower than the women . this texture is

Monophony

Explanation:

"monophonic. Explanation: Since in this choir, the men and women are singing nothing more than a melody, this texture is called monophony. Apart from that, it is also worth noting that since the men sing one octave lower than the women, they are singing at an octave and not in unison." - Google.

I hope this helps.