B
Explanation
Sodium Fluoride
The answer is Paramecium.
The paramecium is a unicellular ciliated protozoan. They are
often found in fresh water and brackish water areas. They have the elongated
shaped that looks like a rod and has the color violet under the stain because it signifies that it is positive.
Factory Emissions is going in the wrong direction. The arrow should be pointing upward, as factory emissions release carbon into the atmosphere.
