C-09-Q087mediumsingle_mcqফিটকিরির সংকেত—aK2SO4⋅Al2(SO4)3⋅24H2O\mathrm{K_2SO_4 \cdot Al_2(SO_4)_3 \cdot 24H_2O}K2SO4⋅Al2(SO4)bAl2O3\mathrm{Al_2O_3}Al2O3cKCl\mathrm{KCl}KCldNaCl\mathrm{NaCl}NaCl