The correct answer is:
O b. It was an easier way to lure Winston into questionable ideas of the memorable past.
Mr. Charrington disguised himself as a much older person to create a sense of nostalgia and invoke a longing for the past in Winston. By appearing as an older individual, Mr. Charrington was able to establish a connection with Winston and exploit his desire to remember and relive moments from a time before the Party's control. This disguise made it easier for Mr. Charrington to manipulate Winston's emotions and draw him into the forbidden world of the past, ultimately leading him into questionable ideas and actions that challenged the Party's ideology.