Which of the following system and data conversion strategies provides the GREATEST redundancy?

Which of the following system and data conversion strategies provides the GREATEST redundancy?

A.
Direct cutover

B.
Pilot study

C.
Phased approach

D.
Parallel run

Explanation:
Parallel runs are the safest-though the most expensive-approach, because both the old and new
systems are run, thus incurring what might appear to be double costs. Direct cutover is actually quite

risky, since it does not provide for a ‘shake down period’ nor does it provide an easy fallback option.
Both a pilot study and a phased approach are performedincrementally , making rollback procedures
difficult to execute.