A drawback of ESG index-based investment strategies is that they rely on established datasets for construction that lack historical data.

Rely on established datasets for construction that lack historical data (C): ESG indices are often based on datasets that have only recently started to be compiled comprehensively. This lack of long historical data can make it challenging to perform back-testing and historical performance analysis, which are crucial for investment strategies.

Focus only on environmental factors (A): ESG indices typically encompass environmental, social, and governance factors, not just environmental ones.

Cannot accommodate factor-based investing styles (B): ESG indices can be designed to accommodate various factor-based investing styles, including value, growth, and others.