What is the preparation step for wet suspended developer before use?

• A. Let it sit still.
• B. Stir or agitate the water-suspended mixture.
• C. Heat it to boiling.
• D. Expose to light.

Answer: (B)

Uniform suspension before use is essential because wet suspended developer relies on evenly dispersed particles to form a consistent coating. This mixture contains fine solid developer particles in water; if left still, the solids settle to the bottom and the top becomes mostly liquid, causing an uneven film thickness when applied. Stirring or agitating re-suspends the settled solids and distributes them evenly, producing a uniform coating that yields reliable indications. Gentle agitation helps avoid air bubbles that could interfere with the test. Letting it sit would cause separation and inconsistent results, heating to boiling can alter the chemical properties of the developer, and exposing to light can degrade the components.