A patient presented with cough and evening rise of temperature since one month. Which among the following is the definitive diagnostic test for tuberculosis?

Definitive diagnosis depends on the isolation and identification of M. tuberculosis from a clinical specimen or the identification of specific sequences of DNA in a nucleic acid amplification test. Specimens may be inoculated onto egg- or agar-based medium (e.g., Lowenstein-Jensen or Middlebrook 7H10) and incubated at 37degC (under 5% CO2 for Middlebrook medium). Because most species of mycobacteria, including M. tuberculosis, grow slowly, 4-8 weeks may be required before growth is detected. Ref: Raviglione M.C., O'Brien R.J. (2012). Chapter 165. Tuberculosis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.