A. B. container { margin: 0 auto ; width:780px; } C. B. D. container { position: absolute;width:780px; left: 50%; margin-left: -390px; } E. C. F. container { margin: 0 auto ; width: 85%;} G. D. H. container { position: relative;width:780px; right: 50%; margin-left: 390px; }