When Riley left her house in the morning, her cell phone battery was partially charged. The charge remaining in Riley's battery, as a percentage, can be modeled by
the equation B = 40 – 5t, where t is the number of hours since Riley left her
house. What is the x-intercept of the equation and what is its interpretation in the
context of the problem?

The x-intercept of the function is ___ which represents
A. the charge of the battery when Riley left her hours
B. The charge of the battery when Riley woke up
C. The percentage charge that Riley’s phone loses loses each hour
D. The number of hours until Riley’s phone dies