ANSWER: UCO Bank
Explanation:
UCO bank registered the biggest increase in gross NPA against total loans in 2014-2015 becoming the worst performer among public sector banks with Gross NPA to gross advances ratio of the bank increasing to 8.05 percent at the end of March 2015 from 4.47 percent, with accretion of 3.58 on an annual basis. This was followed by IoB and BoM having gross NPA rising to 8.30 percent and 6.18 percent respectively at the end of March 2015. Gross NPA of Dena Bank increased from 3.33 percent to 5.29 percent at the end of 2014-15.