Answer:
[B] The client should invest in ETFs that are issued on a REIT index.
Step-by-step explanation:
ETF represents the Exchange Traded Funds basically these are part of Real Estate Investment Trusts, and these ensure the wide diversification in the investments.
The securities of FNMA and GNMA are more focused on the mortgage area, although these too also relate to the real estate sector, but as it focuses on mortgage returns it is not viable for diversification.
Thus, correct option is Statement B as ETF ensures diversification and then lower depreciation accordingly.