Describe in words the surface whose equation is given. \(\phi = \frac{\pi}{4}\) (select the correct answer)

1)the top half of the right circular cone with vertex at the origin and axis the positive z-axis

2)the plane perpendicular to the xz-plane passing through z = x, where \(x \geq 0\)

3)the plane perpendicular to the xy-plane passing through y = x, where \(x \geq 0\)

4)the base of the right circular cone with vertex at the origin and axis the positive z-axis

5)the plane perpendicular to the yz-plane passing through z = y, where \(y \geq 0\)