Which detail from the article BEST supports the idea that teenagers have significant difficulty adjusting to a sleep schedule that requires them to wake up early?

A
Greater academic performance is expected to lead to higher lifetime earnings among more well-rested students.
B
It would be of value "both in terms of benefiting the public health of adolescents and doing so in a cost-effective manner," she said.
C
"The evidence strongly suggests that a too-early start to the school day is a critical contributor to chronic sleep deprivation" among teens, the AAP wrote in 2014.
D
Nationwide, the average starting time for high school and middle school classes is 8:03 a. m. In some states it's considerably earlier. Louisiana starts classes at around 7:40 a. m., on average.