Concept:The green colour of the water culture solution indicates the rapid multiplication of algae, which interferes with the plant's access to essential nutrients.
Explanation:In a normal water culture experiment, the plant receives dissolved mineral nutrients from the solution.
When the solution turned green, it showed that algae had grown and multiplied in the culture medium.
These algae competed with the plant for the same dissolved nutrients and oxygen.
Because algae multiplied quickly, they consumed most of the nutrients before the plant could absorb them.
The plant therefore became starved of the essential minerals required for its growth and survival.
Eventually, the lack of nutrients weakened the plant and caused its death.
There was no evidence of excess nutrients, insufficient water, or lack of sunlight in the described set-up.
Hence, the most likely cause of death is the algal growth that used up the nutrients.
Answer:C. algal growth in the solution that used up the nutrients
