In the gradient descent iterative algorithm, the values of $x^{k+1}$ and $x^k$ in the update statement

$x^{k+1}=x^k-n^k{f}^{\text{'}}(x^k),$ where $n^k=1$ are:

None of the choices

$x^{k+1}>x^k$ if the curve is increasing

$x^{k+1}>x^k{x}^{k+1}if$ the curve $is$ decreasing

$x^{k+1}>x^{k}if$ the curve $is$ decreasing