Answer: HYPOTHESIS.
Explanation: An hypothesis can be defined as an uncertain statement or ideas explaining an observation, phenomenon or scientific problem that can be tested by further observation investigation or experimentation.
An hypothesis is like a prediction with reasons and explanation.
It basically talks about what will happen in the future based on previously unsatisfactory results or experimentation.
Rainfall is irregular and much of this biome has been turned into farmlands is describing the biome: grasslands.
