What should you always do before changing lanes?

Answer: B — Check mirrors and blind spots

The correct action to take before changing lanes is to check mirrors and blind spots. This step is essential for ensuring that the lane you intend to move into is clear of any vehicles or objects that may not be visible in your mirrors alone. By checking your mirrors, you can see what is happening behind and beside you, while looking at your blind spots allows you to identify any vehicles or obstacles that may be in your way but are not visible in your side mirrors. This practice significantly reduces the risk of collisions during a lane change. It's crucial to reinforce safe riding habits, and thorough checks help you maintain awareness of other road users. By doing so, you are better positioned to make informed decisions about when it's safe to change lanes.