Which statement explains why a molecule of ch4 is nonpolar?
(1) the bonds between the atoms in a ch4 molecule are polar.
(2) the bonds between the atoms in a ch4 molecule are ionic.
(3) the geometric shape of a ch4 molecule distributes the charges symmetrically.
(4) the geometric shape of a ch4 molecule distributes the charges asymmetrically.

The answer is the option (3) The geometric shape of a CH4 molecule distributes the charges geometrically. the CH4 is a tetrahedral with the Carbon atom in the center and the four H atoms in the vertices of the tetrahedral. The C-H bond angles are all identical which makes the molecule perfectly symmetrical and so any dipolar moment will cancel making the molecule non polar.

Tolerance to high levels of salinity

What do you mean by that? like the contents? the thc level?