Given the parametric equations:

x = cos(t), y = sin(t), z = sin(5t)
x = sin(3t)cos(t), y = sin(3t)sin(t), z = t
x = cos(t), y = sin(t), z = ln(t)
x = t, y = 1/(1 + t^2), z = t^2
x = t^2 - 2, y = t^3, z = t^4
x = cos(4t), y = t, z = sin(4t)
Which set of parametric equations represents a helix in three-dimensional space?