<prompt> Preference of epidemiological studies for establishing causality:-RCT Retrospective coho Prospective coho Case control Cross sectionalRCT Prospective coho Retrospective coho Case control Cross sectionalRCT Prospective coho Retrospective coho Cross sectional Case controlRCT Retrospective coho Prospective coho Cross sectional Case control  <response>: Preference of epidemiological studies for establishing causality:- Double blind RCT Retrospective coho Prospective coho Case control cross sectional Ecological study. 