Martha Z. Carnes Director since 2016 Lead Director and Chairman of the Audit Committee Age: 65 Ms. Carnes retired from PricewaterhouseCoopers LLP ( PwC ) in June 2016, where she had a 34-year career with the firm. She was an Assurance Partner serving large, publicly traded companies in the energy industry. Ms. Carnes held a number of leadership positions with PwC including the Houston office Managing Partner. She also served as PwC s Energy and Mining leader for the United States where she led the firm s energy and mining assurance, tax and advisory practices. In these roles, she was responsible for leading the design and execution of the market and sector strategies, business development, compensation, professional development, succession planning, and client satisfaction. As an Assurance Partner, Ms. Carnes had vast experience with capital markets activities and was the lead audit partner on some of the largest merger and acquisition transactions completed in the energy sector at that time. Ms. Carnes also served as one of PwC s Risk Management Partners and was PwC s United States representative on the firm s Global Communities Board. She is a certified public accountant. Since December 2019, she has served as a director of SunCoke Energy, Inc., whose principal businesses are cokemaking and logistics, and is the Chair of the Audit Committee. Since July 2017, Ms. Carnes has also served as a director of Matrix Service Company, a services company that provides engineering, fabrication, infrastructure, construction, and maintenance services primarily to the oil, gas, power, petrochemical, industrial, agricultural, mining and minerals markets, where she chairs the Audit Committee and is a member of the Compensation and Nominations and Governance Committees. She is also a Member Representative for Ohio Valley Midstream, a member managed limited liability corporation engaged in natural gas and natural gas liquids gathering and processing. She is a member of the Board of Trustees at Texas Children s Hospital where she chairs the Brand, Planning and Philanthropy Committee and serves on the Executive Committee and Audit, Risk and Compliance Committee. Ms. Carnes is also a member of the Board of the Barbara Bush Houston Literacy Foundation where she chairs the Compensation Committee. Her financial expertise and experience in working with and auditing public companies in the energy industry, and her operational experience at PwC, a professional services firm, allow her to provide important insight to the Company.