Very clever. I actually knew or could have guessed most links once the answers were revealed

Muslin isn't exactly a term in tailoring or sewing. It's a material used as a lining, a base layer over which another material can be sewn or upholstered, or which can used to make a sort of test garment to check fit. It doesn't really work here because a stitch, a lapel and a dart are all parts of a finished garment that you could point to, whereas muslin is rarely a visible part of a finished garment. Stitch, lapel and dart are also all things that a tailor or seamstress might make in the process of sewing, but they would never "make" muslin.