A
Or, if you don't want the increase in noise from an increased ISO, and can't control the shutter speed, and the subject is moving steadily, follow the subject and shoot. The background will be blurred, the subject will be in focus. (In that situation, you can't have them both in focus at the same time.)- The subject moved: You need to increase the shutter speed to freeze the subject. This usually means either adding more light or increasing the ISO or both. If your camera has a "sports" mode, give that a try.