Answer:
warm temperature
Step-by-step explanation:
I cannot see the choices in your image. I can only see choice A, which is "soil."
"Abiotic factors" are part of the ecosystem that don't have life. However, they have an impact on the life of the biotic factors (living organisms) in the environment. Examples of abiotic factors are: sunlight, temperature, climate, soil, humidity, wind, etc.
"Boreal forests" are abundant on the Earth's Northern Hemisphere. The climate here is generally cold, which doesn't allow some trees to survive. It is totally opposite to the warm temperature and high humidity that you can feel in the "tropical forests." Such factors allow many plants and animals to survive.
Clearly, the boreal forests lack the "warm temperature" that the tropical forests have.