Next to the statues and the head, the slab seems unimpressive at first glance. It is roughly the size of a tabletop-three feet nine inches long, two feet four and a half inches wide, and eleven inches thick. But many experts would say that this rather small piece of rock was more valuable than any of the larger objects in the room. For it is the famed Rosetta Stone, which gave nineteenth-century scholars their first key to the secrets of ancient Egypt.

—The Riddle of the Rosetta Stone,
James Cross Giblin

Which statement is an opinion?

A: It is roughly the size of a tabletop . . .
B: [T]his rather small piece of rock was more valuable than any of the larger objects in the room.
C: Next to the statues and the head
D: three feet nine inches long, two feet four and a half inches wide, and eleven inches thick.