When Ashley left her house in the morning, her cell phone battery was partially charged. Let BB represent the charge remaining in Ashley's battery, as a percentage, tt hours since Ashley left her house. A graph of BB is shown below. Write an equation for BB then state the yy-intercept of the graph and determine its interpretation in the context of the problem.

B = _____

The y-intercept of the function is ___ which represents

(A) the number of hours until Ashley's phone dies.
(B) the charge of the battery when Ashley left her house
(C) the percentage charge that Ashley's phone loses each hour
(D) the charge of the battery when Ashley woke up.