Final answer:
The geranium in question is likely dying because it's suffering from a disease, as indicated by the yellow blotches on its leaves and the fact that treatment improves its condition.
Step-by-step explanation:
The question revolves around determining why the geranium sent as a get well gift to Eli is dying. Given the context provided from a reference text that describes the geranium as having 'yellow blotches' all over its leaves and an action taken where 'Aylmer poured a small quantity of the liquid upon the soil in which it grew,' leading to an improvement in the plant's condition, it's possible to infer the primary issue with the plant. Furthermore, comparing to other plant scenarios presented, the health of a plant can be affected by various factors including improper watering, the presence of disease, soil condition, and interference with photosynthesis due to external substances like paint.
For Eli's geranium, diseased with yellow blotches, it indicates that the correct answer is most likely suffering from a disease (Option C). It is less likely related to watering issues, poor soil, or lack of sunlight since the application of a liquid treatment led to an improvement.
Lastly, in the context of a flawed experiment described, it's evident that it's critical to control for variables such as light exposure when investigating the effects of substances like detergent on plant growth. This is also a reminder of the importance of scientific methodology and the potential of Type I errors in experimental conclusions.