<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _resolve_array_type(self):
 """Return one of the ARRAY_TYPES members of DIMENSION_TYPE. This method distinguishes between CA and MR dimensions. The return value is only meaningful if the dimension is known to be of array type (i.e. either CA or MR, base-type 'enum.variable'). """

        next_raw_dimension = self._next_raw_dimension
        if next_raw_dimension is None:
            return DT.CA

        is_mr_subvar = (
            next_raw_dimension._base_type == "categorical"
            and next_raw_dimension._has_selected_category
            and next_raw_dimension._alias == self._alias
        )
        return DT.MR if is_mr_subvar else DT.CA