Which step is essential before changing lanes to ensure a safe merge?

Answer: B — Signal, check mirrors and blind spots, ensure there is space

Before changing lanes, you must communicate your intention and verify there’s room to merge safely. Start by signaling so other drivers know you plan to move. Then check your mirrors to gauge traffic behind and beside you, and perform a blind-spot check to catch any vehicle that isn’t visible in the mirrors. Finally, ensure there’s enough space in the target lane to merge without slowing or forcing other drivers. If there isn’t, wait until a safe gap opens. This sequence prevents surprises, reduces the risk of cutting someone off, and avoids triggering sudden braking or blocking the lane. Hurrying into a lane, braking sharply before merging, or stopping in the lane creates hazards and disrupts traffic.