If the diesel engine turns over by compressed air but it does not fire or stops after a few revolutions; one of the following IS NOT a possible cause, the other four (4) are possible causes. Choose and mark the answer which is NOT a cause.

A
Lack of fuel
B
Filter in the fuel pipe stopped up
C
Governor is without oil pressure
D
Air intake holes in slide valve bushes are stopped up
E
Stop-cock in fuel pipe is closed