Which type of REIT specializes in owning specific building types like apartments?

Equity REITs are the correct answer because they specialize in owning and managing income-producing real estate properties, which often include specific types of buildings like apartments, shopping centers, and office buildings. These REITs primarily generate revenue through leasing space and collecting rents on the properties they own. Equity REITs are involved in the acquisition, development, and management of real estate, making them a direct player in the real estate market.

In contrast, mortgage REITs focus on financing real estate by lending money to property owners and developers or purchasing existing mortgage loans, rather than owning the properties themselves. Commercial cap REITs is not a commonly used term in the industry, and tax-deferred REITs do not refer to a specific classification but rather to a tax treatment aspect in certain cases. Therefore, equity REITs is the appropriate choice for identifying those that specialize in owning specific building types like apartments.