A: Motorcykel has its own lane but because of the truck the motorcykel becomes a high risk as the motor cykel might drive onto your road
B: The truck is now changing lanes into your lane. Thus this pose a bigger risk for you.
C: Intersection is concealed by the truck. Thus there might by pedestrains crossing with out you seeing them. The pedestrian crossing is still a far way ahead. Thus its not an immediate risk
D: The car has its own lane, thus there is no real risk

Thus: Both A and B creates a risk, thus risks does not always happen individually but can be combined