Concept:
Different yarn numbering systems are used in the textile industry depending on the type of fibre and the spinning system.
The two most common systems are:
• Denier System (Direct System)
• Cotton Count or English Count (Indirect System)
In the Denier System, the yarn count is defined as the weight in grams of \(9000\) metres of yarn.
\[
\boxed{
\text{Denier}=\frac{\text{Weight (g) of }9000\text{ m}}{}
}
\]
In the Cotton Count (Ne), the count is defined as the number of \(840\)-yard hanks per pound of yarn.
\[
\boxed{
Ne=\frac{\text{Number of }840\text{-yard hanks}}{\text{Weight in pounds}}
}
\]
Since these systems are based on different units, a conversion constant is required.
Step 1: Recall the conversion formula.
The standard relationship between Denier and Cotton Count is
\[
\boxed{
Ne=\frac{5315}{\text{Denier}}
}
\]
or equivalently,
\[
\boxed{
\text{Denier}\times Ne=5315.
}
\]
Thus, the conversion constant between the Denier system and the Cotton count system is
\[
\boxed{5315.}
\]
Step 2: Compare with the given options.
Among the given values,
\[
\begin{aligned}
4315 &\quad \text{Not the conversion constant}
2315 &\quad \text{Incorrect}
5315 &\quad \text{Standard conversion constant}
6315 &\quad \text{Incorrect}
\end{aligned}
\]
Hence, the standard conversion constant is
\[
\boxed{5315.}
\]
Step 3: Identify the correct option.
The numerical value obtained corresponds to
\[
\boxed{\text{Option (C).}}
\]
Step 4: Final Answer.
Therefore, the constant used for conversion from Denier to Cotton system is
\[
\boxed{5315.}
\]
Hence,
\[
\boxed{\text{Option (C) is the correct answer.}}
\]