A qataa is defined here purely by structure and placement, four lines, and either sitting inside a ghazal or standing alone outside any longer poem, with no mention anywhere of its style or ornamentation.
Since three options describe structural facts drawn straight from the definition and one option introduces a stylistic quality the passage never mentions, the odd one out is that it is embellished.
Poetic Devices: Identify the poetic device used in the following line: "The wind whispered through the trees."