S&P Global Ratings caps equity credit on hybrids at 15% of total adjusted capital (debt + equity). To maximize favorable equity credit without exceeding the cap, the company should not exceed 15% of adjusted capital in hybrids. Since options are 0,25,50,75,100, the appropriate practical choice under the cap is 0% or 25% would exceed. The question asks to what extent should utilize hybrid bonds relative to cap. It would be best to stay within cap, i.e., 15%, but since 15% is not an option, the closest compliant choice is 0%, meaning no hybrids. Therefore, answer: 0% </analysis> 
<final><answer>0%</answer></final>