I believe the correct answer is E. bas-relief.
<span>bas-relief (meaning: low relief) is one of the
sculpture technique, alongside high-relief and intaglio, in which figures and elements
are just barely more distinguished than the background (usually overall flat). Bas-relief technique is really old, the earliest
known bas-reliefs are on the walls of caves and can also be found in Roman or
Greek sculpture (for example: bas-relief sculptures of Poseidon, Apollo and
Artemis on Parthenon).</span>
They used bright pastel colors is probably my best guess, but if that were the case I’m sure you would’ve picked that right?
