Optimal Execution Strategy for Portfolio Rebalancing

Margaret is a portfolio manager at a wealth management firm. After evaluating her firm's exposure to various market sectors, she decides to rebalance her clients' portfolios in order to minimize trading costs while adhering to desired investment strategies. She has identified three potential execution strategies: cutting orders to achieve liquidity, using algorithmic trading to exploit market inefficiencies, and executing trades at the close of trading hours to minimize price impact.

Given her clients' objectives and the current liquidity conditions in the market, what is the most suitable execution strategy for Margaret to adopt in order to achieve optimal cost-effectiveness and efficiency in trade execution for her rebalancing task?