Explanation:

• Option A is incorrect because multi-market indexes typically include indexes from various countries and are designed to represent multiple security markets, including geographic regions, economic development groups, or even the entire world. They are not suitable benchmarks for a single-country ETF.

• Option B is incorrect because a small-cap growth index is a style-specific index, not a multi-market index.

• Option C is correct because multi-market indexes, which often comprise indexes from different countries, serve as effective benchmarks for measuring risk-adjusted performance. They are particularly useful for calculating the beta of a global stock manager's portfolio, as they provide a passive alternative with the same level of systematic risk.