The correct answer is option 1: 1/7.
To identify the scale factor, you can divide the length of the model by the corresponding length of the skateboard.
In this case, the length of the skateboard is 28 inches, and the length of the skateboard model is 4 inches.
Scale factor = Model length / Skateboard length
Scale factor = 4 / 28
Simplify the fraction:
Scale factor = 1 / 7
So, the correct answer is option 1: 1/7.