If the installation of the BAK-12 is going to last over a year then:

The correct choice is that the energy absorber can use either a permanent or semi-permanent configuration. This flexibility is crucial when considering the duration of the installation, as it allows for adjustments based on operational needs and conditions. A permanent installation may be more suited for long-term use, ensuring stability and durability, while a semi-permanent configuration can offer the advantage of easier removal or relocation if operational requirements change.

This option stands out as it accommodates varying contexts and allows for practical decision-making based on factors such as the specific location where the BAK-12 is installed, maintenance considerations, and the anticipated duration of use beyond one year. The ability to choose between these configurations optimizes efficiency and effectiveness in managing the energy absorber's application within the system.