Which of the following best describes wave-particle duality?

Wave-particle duality is a fundamental concept in quantum mechanics that describes how every particle or quantum entity, such as light, exhibits both wave-like and particle-like properties depending on the experimental conditions.

In the case of light, experiments such as the double-slit experiment demonstrate its wave nature, as light can produce interference patterns characteristic of waves when passed through two slits. Conversely, phenomena like the photoelectric effect reveal light's particle characteristics, indicating that light can be thought of as consisting of discrete packets of energy called photons.

Therefore, the correct answer captures this dual behavior, illustrating that light is not limited to either being a particle or a wave exclusively, but rather shows both sets of properties under different circumstances. This duality is a cornerstone of modern physics, emphasizing the complexity of the behavior of light and other quantum entities.