1 tire line. 42x13.50R17 tires sized to your wheels and your car.
A 42x13.50R17 stands 42 inches tall and 13.50 inches wide on a 17 inch rim, the metric equivalent is 343/93R17. A tire size only makes sense next to a wheel width and a car. 42x13.50R17 mounts on a range of widths, and the overall height decides whether the speedometer and the fender stay happy.
1 line carries 42x13.50R17, from Nitto. The tire has to stay near your car's stock height and mount on your wheel width, so pick the car and the wheel set and the page keeps only the 42x13.50R17 lines that do both.