When the interviewer can understand your significant client pain points, and how you overcame them, they can see the level of responsibilities you currently have. This question, if responded to correctly, also gives you the opportunity to help the interviewer picture you in their role with Accenture. Walk the interviewer through your client situation, and share with them how you overcame the hurdle with professionalism and poise.
"I recently had a client who wanted to control every aspect of my work, as opposed to being open to the process. He was very hands-on, which is great; however, not receptive to change. I held a one-on-one meeting with him to discuss the situation head-on. Professionally, I let him know that if he disallowed my process, he would not get the return for which he was seeking. The client apologized for the controlling behavior and, from that point, gave me the room to work that I needed."
"The most challenging client profile is, for certain, the defensive client. I am sure you know the type. The client who argues everything and refuses to look at the hard data, while bringing emotion into every conversation and process. When this occurs, I firmly yet professionally remind the client that past behavior will yield past results. I ask them to revisit why they hired me, or my firm. Then, I have them recommit to our process before I proceed."