The correct option is B (1,1√2)
Any plane through (1, 0, 0), (0, 1, 0) can be taken as
x1+y1+zc=1
D.R.’s of normal to this plane are 1, 1, 1c
This plane is inclined at an angle π4 with the plane x + y = 3
∴cos(π4)=1+1+0.1c√12+12+1c2√1+1⇒4c1(2c2+1)2=12
⇒12 i.e., c =±1√2
∴ D.R.’s of normal of the required plane are (1,1,√2) or (1,1−√2)