Which metal bicarbonate does not exist in solid state?

(P) LiHCO₃  (Q) Ca(HCO₃)₂  (R) Zn (HCO₃)₂  (S) NaHCO₃  (T) AgHCO₃

The metal bicarbonates  (LiHCO₃),  Ca(HCO₃)₂, Zn(HCO₃ )₂,  and AgHCO₃

 do not exist in solid form. The metal bicarbonate, however, is NaHCO₃ in solid form. Due to their strong electropositivity, alkali metals are the only elements that can produce stable solid bicarbonates. However, lithium does not form solid bicarbonate due to its less electropositive nature.