\(\text{Gradient is positive (slopes from bottom left to top right).}\)

\(\tan\,45^{\circ} = 1\)

\(\therefore\ \text{Gradient is 1}\)

\(\Rightarrow C\)

\(\text{Gradient is negative (slopes from top left to bottom right).}\)

\(\text{The line cuts the \(x\)-axis at an acute angle =}\ 90-60=30^{\circ}\) 

\(\tan\,30^{\circ} = \dfrac{1}{\sqrt3}\)

\(\therefore\ \text{Gradient is}\ -\dfrac{1}{\sqrt3}\)

\(\Rightarrow D\)