The proposed benefit that is most likely to influence senior management approval to reallocate budget for a new security initiative is the reduction in residual risk, as it indicates the expected value and outcome of the initiative in terms of reducing the risk exposure and impact to the level that is aligned with the risk tolerance and appetite of the organization. The other options are not the most likely benefits, as they may not reflect the actual or optimal risk reduction, or may not be relevant or measurable for the senior management, respectively. References = CRISC Review Manual, 7th Edition, page 111.