1. The amount of trees in our area is decreasing by \( 10 \% \) every year. If there are \( 20,000 \) trees to begin with, then what is the equation that would match this situation?
A. \( y = 20,000 ( 0.1 ) ^ {x }\)
B. \( y = 20,000 ( 0.9 ) ^ { x }\)
C. \( y = 20,000 ( 10 ) ^ { x }\)
D. \(y = 20,000 ( 90 ) ^ { x }\)