What brevity term signifies acquisition of laser designation or indicates that the platform is laser spot tracker (LST) capable?

The correct choice is associated with the term "Spot," which signifies the acquisition of laser designation or indicates that the platform is capable of laser spot tracking (LST). In military terminology, when a unit or platform obtains a visual lock on a laser designator's spot, it communicates that the laser energy is being recognized and can be utilized for targeting. This is crucial for precision strikes and ensuring that the designated target is accurately engaged.

Other terms like “Capture,” “Contact,” and “Acquire” have different meanings in the context of targeting and guidance systems. "Capture" may refer to obtaining a specific target or data but does not specifically indicate laser tracking. “Contact” typically describes the identification or observation of a target but lacks the specificity of laser designation. “Acquire” is more general and can refer to the initial detection of a target, but does not convey the specific action of recognizing a laser designator. Therefore, "Spot" is the term that most accurately conveys the laser tracking capability being referred to in the question.