I'm 100% that the answer is D, thermal conductivity.
It was either C or D but D makes more sense than C does
so your answer is D
A short period of time, after the onset of puberty. The first mature eggs starts to be released from the ovaries during menstruation. Menstruation may first occur during the start of puberty in women, it may start as early as 8 years old and can start late as 16 years old. Menstruation is the process wherein not fertilized eggs are being broken down and released from the body.