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 underpinning of this phenomenon hinges on considering the ensemble average of expectation values of the intrinsic angular momentum resulting from using the S-O Hamiltonian, as these expectation values vary harmonically in a strong field. Its namesake spectrum corresponds to a proper limit of the Larmor equation. It is of especial utility in studying ring flipping in cyclic hydrocarbons and, in 1985, it was used to determine the structure of fullerene. Proteins are frequently studied using its namesake spectroscopy, which produces a graph of chemical shift as a function of applied frequency. FTP, identify this phenomenon in which atoms have large responses to certain frequencies of applied fields; the basis for MRI's.
A:
Science