单选题
下列图形最有可能是哪段代码执行后的结果？（ ）
A
import turtle
turtle.forward(100)
turtle.left(90)
turtle.circle(50,180)
turtle.down()
B
import turtle
turtle.forward(100)
turtle.left(90)
turtle.circle(50,-180)
turtle.down()
C
import turtle
turtle.forward(100)
turtle.left(90)
turtle.circle(50,90)
turtle.down()
D
import turtle
turtle.forward(100)
turtle.left(90)
turtle.circle(50,-90)
turtle.down()