Answer:
d. it is the oldest known bronze effigy
Step-by-step explanation:
According to a different source, the options that are included in this question are:
a. it is very expensive
b. it is so life-like
c. because of Rudolf of Swabia's role in history
d. it is the oldest known bronze effigy
Rudolf of Swabia was an "alternative" king in Germany during the 11th century. His tomb is a particularly important example of Romanesque art. It is considered the oldest known bronze effigy, and its metalwork is characteristic of the artistic developments of the period. The sculpture also reflects an unprecedented understanding of the human body in art.