Aplant survives in a tropical rain forest. when placed in a temperate forest, it
dies within a year. what is the most likely characteristic of this plant?

The plant needs very stable weather. The weather of tropical rainforests is very stable, having high humidity and temperatures that exceed 18 °C during all months of the year. A plant that is endemic to tropical rainforests and dies within a year in temperate forest most likely needs a very stable weather to survive.
Temperate forest have very unstable weather, with summers that have an temperature average of 21°C and winter temperatures that are often below freezing.