The correct answer is B) More flexible. Electrical power is preferred over mechanical power for driving heavy machinery on drilling rigs because it provides more flexibility in terms of power transmission and control. Electrical motors can be placed closer to the point of use, allowing for a more compact and adaptable design of the machinery. This flexibility is crucial in the dynamic and challenging environment of offshore drilling rigs, where the ability to easily reconfigure and adjust the power systems is essential for efficient and safe operations. The other options are not as relevant or accurate. Electrical power is not necessarily lighter than mechanical power, and the maintenance requirements can vary depending on the specific system. While electrical power may be more fuel-efficient in some cases, this is not the primary reason for its preference on drilling rigs.