We used different learning rates for training a neuron using gradient descent learning. The figure below shows the learning curve $($i$.$e$.,$ the cost over iteration$)$ for every learning rate. Which of the learning rates is a better choice?

$0\mathrm{.}01$

$0\mathrm{.}003$

$0\mathrm{.}001$

$0\mathrm{.}0001$

$0\mathrm{.}03$

$0\mathrm{.}0003$