The correct answers are (i) C. exorbitance, (ii) E. futility, and (iii) I. yield no tangible utility.

Explanation
- Blank (iii): Let's start with the second half of the sentence, which outlines the "two unflattering inferences." The first group of buyers consists of people so incredibly wealthy that they can casually "sink capital into assets that [blank (iii)]." The contrast is with the second group, who "borrow heavily to finance a spectacle of riches." This means the first group is literally wasting or tying up money in something completely unproductive. I. yield no tangible utility fits perfectly, indicating that these assets don't actually do anything practical or generate a return. (May accrue in worth is positive and contradicts the "unflattering" setup; bespeak the owner's discernment also implies positive taste/wisdom).
- Blanks (i) and (ii): The first clause introduces superyachts by defining two matched traits that lead directly to these unflattering inferences (extravagant waste or superficial vanity).
- C. exorbitance (extreme excessiveness/cost) describes the financial reality of the yachts, which perfectly sets up the "fortunes so vast" clue.
- E. futility (pointlessness or uselessness) perfectly mirrors the conclusion in blank (iii) that these vessels serve no practical purpose, balancing out their "stunning" but empty nature.