In the compound khso4, there is an ionic bond between the(1) kh+ and so42- ions(2) khso3+ and o2- ions(3) k+ and hs- ions
(4) k+ and hso4- ions

The answer is (4) K+ and HSO4- ions, because the two radical ions bond to create KHSO4. 

It also makes sense chemically speaking, because KH+ and SO4^2- cannot create a non-charged molecule, and naturally speaking all compounds that are not ions want to balance out their charges.

In an ionic compound, we have a reaction between a negative and a positive atom. 

Therefore, we automatically can conclude that our answer is (4) K+ and HSO4- ions
Hope I helped. :)

Oh nskskakaaka