when but so and

Choose the best answer to complete the passage:

Headache is a very common disease. The symptoms (1)…….. a headache are various. People may (2)……….. pains only one side of the head. Sometimes when the pain goes away, the head is sore. People have a headache (3) …………. they work too hard or they are too nervous about something. (4)……….. can help cure the disease but people usually have to do more than taking tablets. They can prevent headaches by changing their diets or their (5)…………… or simply by going to bed.

Question 3: