Final answer:
The highway-rail grade crossing offense mentioned is failing to have sufficient space to drive completely through the crossing. Inoperative brake lights and operating a CMV during an out-of-service order are not specific to rail grade crossing but are traffic violations.
Step-by-step explanation:
The question asks about highway-rail grade crossing offenses, which are specific violations related to railroad crossings. The correct answer is not within the provided choices, as the offenses listed such as inoperative brake lights or operating a CMV during an out-of-service order, do not specifically pertain to highway-rail grade crossings. However, failing to have sufficient space to drive completely through the crossing is a highway-rail grade crossing offense. This is because blocking a railroad crossing poses a safety risk and can lead to serious accidents. It is crucial for all drivers, especially those operating commercial motor vehicles (CMVs), to ensure the other side of the crossing is clear before proceeding.