Stop before entering the junction: Correct
If there is a stop sign or a red traffic light at the junction, you are required to stop before entering, regardless of your intention to turn right. In such cases, stopping is mandatory to ensure safety and to comply with traffic regulations. If the traffic signals or road signs indicate that you must stop before proceeding (such as a stop sign or red light), then you must stop before entering the junction.
Make the turn following general right of way rules: This option is generally correct in most situations, but not always. In normal cases, when there are no stop signs or signals, you would make the turn while following the right of way rules. However, if there is a stop sign or red traffic light, you must stop before entering the junction, even if you are turning right.
Keep going, as the traffic light is after the junction: This is incorrect because you are required to obey the traffic control devices at the junction itself, such as a stop sign or red light, regardless of the position of a traffic light beyond the junction.