In which state is a polarized nerve fiber found?

Consider the statements as True/False:
$I$. The axoplasm inside the axon contains a high concentration of $K^{+}$ and negatively charged proteins.
$II$. The axoplasm inside the axon contains a low concentration of $Na^{+}$.
$III$. The fluid outside the axon contains a low concentration of $K^{+}$.
$IV$. The fluid outside the axon contains a high concentration of $Mg^{++}$ and negatively charged proteins.
The correct option is:

$A$ neuron becomes an electrically charged cell primarily due to the differential permeability and diffusion of which ion?

During the conduction of a nerve impulse along a neuron,what is the nature of the electrical charge on the inner side of the plasma membrane?

How does the conduction of a nerve impulse occur?

In the resting stage of a neuron,the concentration gradient allows the diffusion of which ions?