Concept:
Sodium hydroxide (NaOH) is widely used in textile wet processing, especially in scouring, mercerization, and bleaching processes. In industrial applications, it is preferred in solid form for ease of storage, handling, and controlled dissolution.
Step 1: Understand industrial requirement.
Industries require NaOH that is:
• Stable for storage
• Easy to transport
• Quickly soluble in water
Step 2: Evaluate forms.
• Flakes → widely used industrial form
• Pellets → less common in textile wet processing
• LR grade → not standard physical form
• Solvent → incorrect chemical form
Step 3: Final conclusion.
NaOH flakes are the most commonly used industrial form.
\[
\boxed{\text{NaOH Flakes}}
\]
Thus,
\[
\boxed{\text{Option (A) is correct.}}
\]