Typical diesel injection pressure: choose the closest standard value. Select the approximate fuel injection pressure used in conventional diesel engines.

Concept/Approach
Traditional mechanically-controlled DI diesels commonly use injection pressures in the ~150–250 bar range. Modern common-rail systems can exceed 1000 bar, but for textbook basics, ≈150 bar is the representative value among the given choices.

Elimination
10 bar and 100 bar are too low; 500 bar is high for older conventional systems.

Final Answer
150 bar.