Final answer:
The weathering of headstones can vary due to differences in the materials used.
Step-by-step explanation:
The variation in weathering between the headstone on the right and the headstone on the left can most likely be attributed to differences in the materials used to make each headstone.
Stone materials such as granite, marble, and limestone are commonly used for headstones, and each type of stone weathers differently over time.
For example, granite is a durable and weather-resistant stone that tends to hold up well over time, while marble is softer and more prone to erosion and discoloration.