The figure below shows a 4 m depth pool containing water and mercury at the lower right of the diagram below. Assuming that pressure variations are caused by water and mercury weight only, indicate which of the following options are correct. 

Note: p_x denotes pressure at point x and ρ is density. Points a, b, c and d are at the same depth. Bottom locations (A,B,C and D) are all at the same depth but deeper than a,b, c and d.