Why is Jim unable to use his excess liability policy before his commercial general liability policy?

Jim is unable to use his excess liability policy before his commercial general liability policy because the excess liability policy is designed to provide coverage after the limits of the underlying commercial general liability policy have been exhausted. This means that the excess liability policy acts as an additional layer of coverage that kicks in only once the base policy's limits have been reached. The purpose of this structure is to ensure that the primary coverage is utilized first for claims, providing a more effective and efficient approach to risk management.

The other options do not accurately reflect the relationship and intended purpose of these insurance policies. For example, a lower limit does not inherently determine the precedence of policy use, since excess policies are often structured to provide higher limits. Coverage of different types of risks isn't relevant in this context, as both policies contribute to the overall liability coverage but serve different functions. Finally, the idea that an excess policy cannot be claimed for lawsuits misrepresents its purpose, which is indeed to provide additional coverage for legal claims, but only after the base policy has been exhausted.