if my memory is correct, the question is asking which choice cannot help the risk "aggregation".brother i forgot what i chose for this particular question but i m sure i didnot choose "centralisied database"....as per my logic this question deals with ERM and in ERM its better to have decentralisation as it helps to delegate the risk duties throughout the firm.
a) Centralized database
b) daily reporting with cutoff time
c) independent tested system for each
d) using a unify name and identifier in each system
"tested system" seems to be correct at first sight.
the tricky point is "independent system" make it more difficult to "aggregate " data/risk.