Among the given statement, statement (c) is incorrect. Thecurrent model that we have is of three services having their ownchiefs, while one of them officiates as the chairman, chiefs of staffcommittee (COSC) based on his seniority in the rank of chief (thechairman does not function as the Chief of the Defence Staff). Thechairman, COSC is served by Headquarters Integrated DefenceStaff (IDS). He, thus, wears two hats – his own service and that of the chairman COSC