The crystal structure of an ionic compound depends on the . a) sizes of cations and anions. b) ratio of cations to anions. c) masses of cations and anion. d) both a and b

The crystal structure of an ionic compound depends on the sizes of cations and anions, as well as the ratio of cations to anions. The ratio of the cations and anions need to be even, otherwise, the crystal won't form.
 
So the answer would be D, both A and B. 

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