**Answer:**

The correct answer is option B, Davisson and Germer.

**Explanation:**

**1. Introduction**

In the early 20th century, scientists were trying to understand the nature of particles like electrons. The debate was whether these particles behave only as particles or also exhibit wave-like properties. This debate was resolved through the experiments conducted by Davisson and Germer in 1927.

**2. Davisson and Germer Experiment**

Davisson and Germer performed an experiment to study the scattering of electrons by a crystal lattice. They used a beam of electrons and directed it towards a nickel crystal. The electrons were scattered in different directions after interacting with the crystal lattice.

**3. Observations**

The key observation made by Davisson and Germer was the presence of interference patterns in the scattered electrons. Interference patterns are a characteristic of waves and not particles. This observation indicated that electrons have wave-like properties.

**4. Explanation of the Observation**

The interference patterns observed by Davisson and Germer can be explained by considering the wave nature of electrons. According to the de Broglie hypothesis, particles like electrons have both particle-like and wave-like properties. The wavelength associated with a particle is given by the de Broglie wavelength equation:

λ = h / p

where λ is the wavelength, h is Planck's constant, and p is the momentum of the particle. The de Broglie wavelength of electrons is very small due to their small mass and high momentum.

When the electron beam interacts with the crystal lattice, the electrons are scattered in different directions. Due to the wave nature of electrons, the scattered waves interfere with each other, resulting in the observed interference patterns.

**5. Significance of the Experiment**

The Davisson and Germer experiment conclusively demonstrated that electrons have wave-like properties, supporting the wave-particle duality of matter. This experiment provided strong evidence for the de Broglie hypothesis, which was a major advancement in the understanding of quantum mechanics.

**Conclusion**

The experimental evidence provided by Davisson and Germer in 1927 confirmed the wave-like properties of electrons. This experiment played a crucial role in establishing the wave-particle duality of matter and contributed to the development of quantum mechanics. Hence, the correct answer is option B, Davisson and Germer.