What sector experienced the highest percentage of Lloyd's US business in 2013?

The correct answer highlights that surplus lines constituted the largest share of Lloyd's US business in 2013. Surplus lines insurance refers to coverage provided for risks that are not adequately addressed by standard insurance markets. In many instances, this kind of insurance is necessary for non-standard or high-risk businesses that require specialized coverage.

Given the evolving nature of various industries in 2013, surplus lines became increasingly vital for addressing unique or unusual risks that were not being met by traditional carriers. This rise can be attributed to several factors, including the growing complexity of business operations and a heightened awareness of unconventional risk profiles by businesses seeking tailored coverage solutions.

As a result, surplus lines insurance offered through Lloyd's established itself as an important component of their US market strategy, significantly influencing the overall business volume. This sector's growth reflects broader market trends where more businesses began to recognize the necessity for specialized insurance solutions in today's dynamic business environment.