To clarify, I am still a bit confused on what you mean by "Option A fails to maintain parallelism between the noun phrase “paintings” and the prepositional phrase “in the Sistine Chapel”; remember, two elements linked by a conjunction (“for example” in this case) must be parallel." In Choice D there still is "paintings" and then "in the Sistine Chapel"...
is it the "those" that builds the parallelism that was missing in choice A? --->replacing "paintings" with "those" --> paintings, such as [paintings] in the Sistine Chapel". Thank you again.
We hope this finds you well.
To answer your query, yes; it is the inclusion of "those" that makes choice D parallel.
We hope this helps.