Appropriate Benchmark for Multi-Asset Portfolio

In the context of portfolio management, effective performance evaluation often involves comparing a portfolio's returns against a relevant benchmark. Consider the following scenario:

A portfolio manager is deciding which benchmark to use to assess the performance of a multi-asset class portfolio that includes equities, fixed income, and real estate. The manager is looking for a benchmark that adequately reflects the risk and return characteristics of the portfolio while providing a fair comparative measure.

Which of the following benchmarks would be the most appropriate for this portfolio?