In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as 'a' for Yes or 'b' for No.

Question: Was the crime rate in London higher than San Francisco the year Mitchison returned to San Francisco? Passage:Mitchison returned to the UK for postdoctoral research at the National Institute for Medical Research (NIMR) in London. In 1988 he returned to San Francisco where he was appointed assistant professor at UCSF. In 1994 he wrote an opinion piece for the journal Chemistry & Biology titled "Towards a pharmacological genetics" which helped to launch the field of chemical genetics. In 1997 he moved to Harvard University to become co-director of the Institute for Chemistry and Cell Biology at Harvard Medical School, where he pioneered phenotype-based screening, discovering the small molecule monastrol the first small-molecule inhibitor of mitosis that does not target tubulin. Monastrol was shown to inhibit kinesin-5, a motor protein. In 2003 he became Deputy Chair of the newly formed Department of Systems Biology, chaired by Marc Kirschner. He works on aspects of mesoscale biology including the self-organization of the cytoskeleton and of cytoplasm. He collaborates extensively with Christine Field on the mechanism of cytokinesis.
a