Which of the indicator diagrams illustrated depicts the condition that should be corrected by retarding only the timing? Illustration MO-0029

Question

Which of the indicator diagrams illustrated depicts the condition that should be corrected by retarding only the timing?  Illustration MO-0029

Accepted Answer

Option A: A. Indicator diagram 'A' displays an excessively high peak pressure and early pressure spike, an operational anomaly directly corrected by retarding the fuel injection timing.