What is a common feature of myths about detecting vampire graves?

The notion that a virginal youth rides a white horse is a common feature in myths about detecting vampire graves, as it draws upon themes of purity and innocence that are often associated with vampire lore. In many cultures, the concept of a pure, untainted individual being able to confront or identify supernatural entities reflects the belief that innocence has the power to combat evil. The imagery of a young, virginal person riding a white horse evokes a sense of otherworldly purity, suggesting that such a person might possess the special qualities necessary to identify or confront a vampire's resting place. This fits within the larger framework of folklore that often characterizes the triumph of good over evil, particularly when it comes to supernatural beings like vampires.

In contrast, the themes presented in the other options do not consistently appear across various vampire myths. The idea of a special flower blooming above a grave, for instance, may relate more to nature’s response to death but lacks the stronger mythological connections tied specifically to vampiric folklore. Similarly, the notion of a child performing a ritual is less frequently encountered; while children and rituals do appear in some myths, they do not hold the same cultural resonance when it comes to vampire detection. The notion of a grave glowing in