【单选题】设R是定义在集合{0,1,2,3}上的关系,R中包含有序对(0,1),(1,1),(1,2),(2,0),(2,2)和(3,0),R的自反闭包为()
A.
{(1,1),(0,0),(2,2),(3,3)}
B.
{(0,1),(1,1),(1,2),(2,0),(2,2),(3,0),(1,1),(0,0),(2,2),(3,3)}
C.
{(0,1),(1,2),(2,0),(3,0),(1,1),(0,0),(2,2),(3,3)}
D.
{(0,1),(2,0),(3,0),(1,1),(0,0),(2,2),(3,3)}