The revision of these two sentences that uses a relative clause is "The orchestra that was seated on stage played a difficult score".
Relative clauses are<u> clauses that start with a relative pronoun</u>. In this case, <u>the relative pronoun that has been used is "that" </u>and <u>the relative clause is "that was seated on stage"</u>. Furthermore, a relative clause is used to identify or define the noun that precedes it. In this case, <u>the noun identified by the clause is "orchestra"</u>. Therefore, the relative clause "that was seated on stage" is postmodifying the noun "orchestra".
<span>A complex sentence contains a subordinate clause or clauses: So, A is correct.</span>
A vignette<span> is a scene or a descriptive sketch. It might focus on a single moment or an image, or it may give a particularly distinct impression of a character or setting. A</span>vignette<span> is a snapshot or a glimpse. ... A </span>vignette<span> differs from a </span>short story<span> in that it doesn't necessarily have all the elements of plot.</span>