Answer:
The correct answer is "D".
The words in the sentence that indicate opinion are:
"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".
Step-by-step explanation:
The verb "seems" is used to express opinion and the adjective "unimpressive" is used to describe the noun "slab". These words refer to the feelings and perceptions of what is being observed. They are words and an expression to show a point of view.