In an ionic bond, electrons are transferred from one stone to another atom (shared).
Because in CH4 the valence electrons of Carbon are being pulled away from the nucleus with the same force (since all hydrogen has the same electronegativity).So charges are equally distributed throughout the atom and the atom is non-polar. In CH3Cl Cl has a different electronegativity than H, so charges aren't equally distributed and therefore the molecule is polar.
The correct letter to your answer would be A
Explanation:
(a) potassium oxide with water
According to reaction,1 mole of potassium oxide reacts with 1 mole of water to give 1 mole of potassium hydroxide.
(b) diphosphorus trioxide with water
According to reaction,1 mole of diphosphorus trioxide reacts with 2 moles of water to give 2 moles of phosphorus acid.
(c) chromium(III) oxide with dilute hydrochloric acid,
According to reaction,1 mole of chromium(III) oxide reacts with 6 moles of hydrochloric acid to give 2 moles of chromium(III) chloride and 3 moles of water.
(d) selenium dioxide with aqueous potassium hydroxide
According to reaction,1 mole of selenium dioxide reacts with 2 moles of potassium hydroxide to give 1 mole of potassium selenite and 1 mole of water.