Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
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Question: The Ghost Dance War was an armed conflict in the United States between the Lakota Sioux and the United States government from 1890 until 1891.

Answer: What year did Ghost Dance War start?


Question: ''Nothing Good Happens After 2 A.M.'' is the 18th episode in the first season of the television series How I Met Your Mother.

Answer: What series is the episode Nothing Good Happens After 2 A.M. part of?


Question: Once acquired, Epstein-Barr virus (EBV), a latent virus, remains in the body for what appears to be the lifetime of the human host. Circumstantial data suggest EBV is involved in clinical disease including malignancies far more often than previously recognized. A serologic test for early antigen (EA) is more specific for diagnosing active EBV disease than the monospot or heterophile test. A case study of active Epstein-Barr infection is reported showing persistently elevated early antigen titers prior to and following malignant transformation.

Answer:
Which virus can be diagnosed with the monospot test?