About Agricultural vehicles, riders and livestock: which statement is WRONG?
The book literally names two classes: some agricultural vehicles at most 25 km/u, others at most 40 km/u.
The rule asks for BOTH: adjusting your speed AND passing with ample sideways distance (1.5 m), precisely to avoid startling the animals.
You can rely on the indicator signal of an agricultural vehicle, just like with an ordinary car.
Behind a tractor with a high-loaded trailer you know one thing for certain: the driver does not see you.
Explanation
trap: signal-is-guarantee assumption. Book p.132 - with agricultural traffic, lighting, indicators and brake lights do not always work; do not blindly assume the vehicle will do what it signals