Which adjustment would you make if a garment is too loose at the seams?

To address a garment that is too loose at the seams, increasing the seam allowance is the appropriate adjustment. A greater seam allowance provides additional fabric to work with which allows for a tighter fit. By making this adjustment, the seam can be taken in, reducing the overall size of the garment in the areas where it is too loose.

Other choices may not effectively solve the issue of looseness. Decreasing the seam allowance would actually reduce the fabric available for taking in, leading to a looser fit. Changing the type of seam might affect the garment's design or construction but would not address the issue of fit at the seams directly. Shortening the fabric length would alter the overall length of the garment rather than adjusting the area where it is loose. Thus, increasing the seam allowance directly targets the problem of excess fabric at the seams, making it the best solution.