The scenario that would most likely lead to the plant's death is a lack of carbon dioxide.
In a sealed environment, the plant would initially be able to perform photosynthesis using the light available and the carbon dioxide present in the container. However, over time, the carbon dioxide levels would decrease as the plant uses it for photosynthesis, and if there are no additional sources of carbon dioxide, the plant would not survive due to insufficient levels for photosynthesis.
While a lack of light would also eventually cause problems for the plant, it typically has enough light initially to help it grow before reaching that point. A lack of oxygen would not be an issue in the short term, as plants produce oxygen during photosynthesis, but they do also consume oxygen during respiration at night. However, it is the depletion of carbon dioxide that would critically affect its ability to perform photosynthesis over time.