Correct option is B
Explanation-
Option a : Radioactive dating of the tree remains
Use of isotopes like C-14 (Carbon-14) to date organic materials. It tells us how long ago a tree died. It is commonly used in archaeology and paleobotany. It tells the age of the tree remains, but does not directly tell when a fire occurred. The tree may have died from various causes like disease, old age, storm, or fire. Even if death was due to fire, it would not tell us about multiple fire events or frequency. It is not suitable for determining fire frequency history.
Option b : Examining the fire scars in growth rings of living trees
This is called fire-scar dendrochronology. Each year, trees add a growth ring. When a fire occurs, it damages the growing tissue, causing visible scars in the ring. By counting these scars and matching ring widths, we can detect how many times fires occurred and can know the exact year of each fire event. It is non-destructive (the tree remains alive), gives precise year-by-year historical record and works very well for long-living tree species like sequoias, pines, oaks, etc.
Most accurate method to study historical fire frequencies.
Option c: Measuring carbon content on the soil surface after fire
Fires leave behind charcoal, ash, and carbon-rich residues in soil and measuring soil carbon may give some evidence that a fire happened. Surface carbon may degrade, erode, or be buried over time. It does not provide clear timelines. It cannot distinguish between multiple fire events over many years and gives very limited or unreliable data for frequency.
Option d: Examining records of evacuation history of the nearby villages
It refers to written or oral history of human evacuations during fires. It is only useful in recent history where people lived and recorded events. In many natural ecosystems (forests, grasslands, wilderness), fires may occur without any human settlement nearby. Records may be incomplete, biased, or missing and cannot reconstruct fire history over hundreds or thousands of years. So, not reliable for true historical fire frequency data.
So, the correct answer is option b - Examining the fire scars in growth rings of living trees.
