In which Indian city was the first pure green hydrogen plant commissioned?

Green hydrogen is hydrogen produced by splitting water through electrolysis using electricity generated entirely from renewable sources (solar, wind, hydro) — unlike grey hydrogen (from natural gas) or blue hydrogen (fossil-based with carbon capture). A plant described as producing "pure" green hydrogen is one certified to a very high purity level (99.999%) via this renewable-electrolysis route.

India's first plant to produce 99.999% pure green hydrogen was commissioned by Oil India Limited (OIL) at its pilot facility in Jorhat, Assam, in April 2022 — ahead of the larger-scale green hydrogen projects later set up by other public-sector companies. Jorhat does not match Hyderabad, Mumbai, or Pune, so none of these three named cities hosts this pioneering plant.

Checking each listed city against the actual record:

• Hyderabad — GAIL's own green hydrogen facility was commissioned only in 2024, and it is located at Vijaipur (Madhya Pradesh), not Hyderabad.

• Mumbai — none of the major green hydrogen commissioning announcements (Oil India, L&T, NTPC, GAIL) are located in Mumbai.

• Pune — similarly has no recognized claim; the pioneering facility was set up in a different state entirely.

• More than one of the above — this would need at least two of Hyderabad, Mumbai, and Pune to each independently host a genuine "first" claim; since none of the three do, this option cannot hold either.

Since the actual site (Jorhat, Assam) is not among the listed cities, and no listed city individually qualifies, the correct choice is "None of the above."