Study the road map for preparation of washing soda and fill up the blanks.
A. `{:(P,Q,R,S,T,U,V),(CaCO_(3), CaO, Ca"(OH)"_(2), NH_(3), NH_(4)OH, NH_(4) HCO_(3), NaHCO_(3)):}`
B. `{:(P,Q,R,S,T,U,V),(CaCl_(2), CaO, Ca(OH)_(2), HCl, HCl, NaHCO_(3), HCl):}`
C. `{:(P,Q,R,S,T,U,V),(CaCl_(2), CaO, CaCO_(3), NH_(3), HCl, NH_(4)Cl, NaHCO_(3)):}`
D. `{:(P,Q,R,S,T,U,V),(CaCO_(3), CaO, Ca(OH)_(2), HCl, Cl_(2), CaCl_(2) , N aHCO_(3)):}`
