Let's match each compound to its corresponding use based on its properties and common applications:
- Benzaldehyde (a): This compound is widely used in the perfume industry due to its pleasant almond-like fragrance. Therefore, the correct match is a-(iii).
- Methanoic acid (b): Also known as formic acid, methanoic acid is used as a preservative, an antibacterial agent, and in electroplating. It is sometimes used in the leather and textile industries. Thus, the correct match is b-(iv).
- Sodium benzoate (c): Sodium benzoate is primarily used as a food preservative to prevent the growth of harmful bacteria. Therefore, the correct match is c-(i).
- Hexanedioic acid (d): Also known as adipic acid, this compound is essential in the production of nylon 6,6, a synthetic polymer used in fibers and plastics. Thus, the correct match is d-(ii).
Therefore, the correct answer is (E) a-(iii), b-(iv), c-(i), d-(ii).