Regarding silicaI) Quartz is amorphous form of silicaII) Silica dissolves in NaOHIII) Silica dissolves in HFThe correct combination is

Quartz is a crystalline form of silicaNOTE: Quartz  Tridymite  Crystobalite  areCrystallineforms   Jaspar  Agate  Onyx  Kieselgar  aretheamorphousforms 1) SiO2+6HF→H2SiF6 Fluosilisicacid +2H2OSiO2 is soluble in HF due to the formation of fluosilicic acid and hence HF is used for ETCHING process2) SiO2 Acid +2NaOH(aq)→Na2SiO3 sodiumsilicate +H2OSiO2 Acid +2KOH(aq)→K2SiO3+H2OSiO2 is soluble in base like NaOH, KOH due to the formation of soluble silicatesSiO2 donot soluble in any other solvents