Step 1: Match Methanoic acid.
Methanoic acid (formic acid) is widely used in the textile and leather industries for dyeing and finishing processes.
Therefore,
\[
\text{Methanoic acid} \rightarrow \text{Textile}
\]
Hence,
\[
a \rightarrow (i)
\]
Step 2: Match Ethanoic acid.
Ethanoic acid is commonly known as acetic acid.
A dilute aqueous solution of acetic acid is called vinegar.
Therefore,
\[
\text{Ethanoic acid} \rightarrow \text{Vinegar}
\]
Hence,
\[
b \rightarrow (iv)
\]
Step 3: Match Hexanedioic acid.
Hexanedioic acid is commonly known as adipic acid.
It is used in the manufacture of nylon-6,6 and other polymers.
Therefore,
\[
\text{Hexanedioic acid} \rightarrow \text{Polymer}
\]
Hence,
\[
c \rightarrow (ii)
\]
Step 4: Match Sodium benzoate.
Sodium benzoate is widely used as a food preservative because it inhibits the growth of microorganisms.
Therefore,
\[
\text{Sodium benzoate} \rightarrow \text{Food preservative}
\]
Hence,
\[
d \rightarrow (iii)
\]
Step 5: Write the correct matching.
\[
a-(i),\quad b-(iv),\quad c-(ii),\quad d-(iii)
\]
Step 6: Final conclusion.
Therefore, the correct matching is
\[
\boxed{a-(i),\ b-(iv),\ c-(ii),\ d-(iii)}
\]
Hence, the correct option is
\[
\boxed{(1)}
\]