Acandle has been burning for 20 minutes and is now 25 cm tall. in an hour it will be 10 cm tall. which equation models the height why of the candle and centimeters, x minutes after it was lit.
a: y -25 = -4(x -20)
b: y-25= -3/8(x-20)
c: y+25= -.25(x+20)
d: y-25= -.25(x-20)