Explanation:

- Acculturation is when people from different cultures come into direct contact and exchange cultural features, but each group still keeps some distinct identity.

- Universalisation is the process by which certain cultural elements become widespread across the world, but not necessarily through direct contact.

- Diffusion is the correct term for the spread of cultural traits from one society to another, often without direct contact.

- Assimilation refers to the process where a minority group gradually adopts the cultural traits of the dominant group, sometimes losing their original identity.

Correct Answer: Option:3, Diffusion