Answer:
Option B, Data from a wide range of time periods must be analyzed.
Step-by-step explanation:
The climate change is studied by the climatologists in relevance to the climatic conditions in the past.
The climate change will remain stable if no external agent is interfering with natural processes, but since the evolution of mankind (billions of years back) it has become essential for scientist to study the climatic condition in those ages or ages much before that in order to work out how human interventions are disrupting the natural phenomenon.
In order to do so, it is very important to predict the actual climatic condition billions or millions of year back . Hence, through scientific design , researchers must try to overcome the limitation of data assessment from wide range of time periods.