A. wood block printing
Wood block printing was an artistic invention that developed later, but the Han Dynasty (206 BCE – 220 CE) is known for significant advancements in various arts, including silk production and early forms of printing techniques. However, the specific technique of woodblock printing is usually associated with later periods, such as the Tang and Song Dynasties. Other options like sculpting, embroidering, and silk production were indeed developed and refined during the Han Dynasty.
If you're looking for the most significant artistic invention specifically attributed to the Han Dynasty, none of the options might perfectly fit, but among those listed, silk production would be a pivotal art form. However, from the options provided, none accurately describe a major artistic invention specifically tied to the Han Dynasty.