Question 56 RVR04 - Master or Mate of LT 200 GRT

The Correct Answer is A. **Explanation for A (Oil level):** Checking the oil level is a fundamental and mandatory pre-start procedure for virtually all internal combustion engines, whether diesel or gasoline. Oil is essential for lubricating moving parts and preventing catastrophic engine damage due to friction and overheating. Starting an engine with low or no oil will lead to immediate and costly engine failure (seizing or major component wear). Therefore, checking the oil level is the absolute minimum requirement before starting. **Explanation for B (Flow of cooling water):** While checking the cooling system (coolant level, not necessarily *flow*) is very important, checking the *flow* specifically requires the engine to be running or a specific external priming system to be operational. The absolute essential check *before* starting is the static level of the coolant/water. Furthermore, for some air-cooled engines (like many small gasoline engines), this check is irrelevant. Therefore, "Flow of cooling water" is not a universal pre-start requirement. **Explanation for C (Exhaust discharge):** Checking the exhaust discharge (i.e., ensuring the exhaust pipe isn't blocked) is an important safety check, especially in industrial or marine settings. However, it is secondary to the primary function of the engine (lubrication) and is not always considered a universal, mandatory pre-start check for all consumer applications in the way oil level is. **Explanation for D (All of the above):** This is incorrect because options B (Flow) and C (Exhaust discharge) are either incorrect interpretations of the necessary pre-start check (B) or are not universally mandatory in the same way the oil level check (A) is. Since A is the single most critical and universally required step, A is the best correct answer when forced to choose only one.