Answer:
Correct option: a (tetrahedral)
Step-by-step explanation:
According to VSEPR theory tetrahedral arrangement comes when central atom have four electrons pair in the valence shell and only in this arrangement electron pair will fell less repulsion that is why it is arranged in this way and VSEPR theory electrons pair are arranged in such a manner that they fell less repulsion.
they might have different number of bond pair and lone pair that depens on the number of bonded to other atom.
Hence opion a is correct.