Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: The logarithm of a quantity undergoing this process with drift is used to model stock prices in the Black-Scholes model. This process is a classic example of a Wiener Process, and the movement of an individual particle via this process can be predicted by the three-dimensional Langevin equation. This process, a stochastic explanation of which was offered in one of Einstein's annus mirabilis papers, was first observed in pollen grains in water. For 10 points, name this random motion of small particles, named for a Scottish biologist.
A:
Science