In this question select all correct options. Which of the following sets are subspaces of R2?
A {(x,y) | x = y}
B. {(0, 0)}
C. {(x,y) | y = 1+ 4x}
D. {(x,y) | x+y = 0}
E {(x,y) | y = 2x}
F {(x,y) | x < y}
G. {(x,y) | x2 + y2 = 0}
H: {(1,y) | y arbitrary number}