Hi @Dimitrova,Mariya ,
Surely that we create list relationships by using lookup columns.
However, lookup column does not support all column types. Single line of text, choice (single value), number, currency, date and time, lookup (single value), person (single value) are supported.
More information about lookup column limitation.
You mention that your column in listA has multiple choice information. If your column type is Choice or Multiple lines of text, with multiple values, it cannot be lookup.
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