[单选题]
An acorn falls from z,jn9i )3)w9,3c hzekri a euwnd-3kha treelv b5e ewm3ls(x c,6 5bl ,f9yoi)q9gt. Compare its kinetic energy K, to its potential enere53tbll9 6,wy, ogcb9)si5(x f qvmelgy U.
A. K increases and U decreases.
B. K decreases and U decreases.
C. K increases and U increases.
D. K decreases and U increases.
