The correct answer is A) ensure your ship will NOT block the channel or obstruct the range while at anchor. This is the correct answer because when anchoring, you must ensure that your vessel does not block the channel or obstruct any navigation aids, such as the range lights shown in the illustration. Blocking the channel or obstructing the range lights could create a hazardous situation for other vessels entering or leaving the port. The range lights are important navigational aids, and you must be mindful of their position and ensure your anchored vessel does not interfere with them. The other options are incorrect because: B) is incorrect as you do not need to wait for the lights to be in line before dropping anchor, as long as you ensure your vessel does not obstruct them; C) is incorrect as you should not drop the anchor immediately without first confirming it will not block the channel or obstruct the range; and D) is incorrect, as the change in the range lights' position may not necessarily indicate that your anchor is dragging.