Final answer:
Sulfur exists as a polyatomic molecule with eight atoms of sulfur at room temperature, having the formula S8.
Step-by-step explanation:
Among diatomic elements, some are polyatomic at room temperature. The most common form of the element sulfur is composed of molecules that consist of eight atoms of sulfur and thus have the molecular formula of S8. Therefore, the correct answer to the question 'Among diatomic elements, some are polyatomic at room temperature, such as sulfur with the formula _____.' is d) S8.