Explanation:

• Option A (Incorrect): The currency of payments is a feature specific to fixed income indexes and does not apply to equity indexes.

• Option B (Correct): Both equity and fixed income indexes can be categorized according to the issuer's economic sector. Similar to equities, fixed-income securities can also be classified based on the issuer's geographic region or the economic development of the issuer's region.

• Option C (Incorrect): The degree of inflation protection is a characteristic specific to fixed income indexes and is not applicable to equity indexes.