What color was the lagoon described as in that sample?

• A. Bright green
• B. Deep blue
• C. Brown
• D. Gray

Answer: (A)

A lagoon’s color often signals what’s happening biologically inside. A bright green look means algae are thriving, thanks to abundant nutrients and sunlight. The chlorophyll in these algae gives that vivid green hue, so describing the sample as bright green points to an algal bloom in the lagoon. If the water were deep blue, it would imply clearer water with less algae; brown would suggest sediment or organic matter, and gray would indicate turbidity from suspended solids. So the bright green description matches the typical visual cue of nutrient-driven algae growth in a wastewater lagoon.