The first series, which was identified in the spectrum of hydrogen is called:

Explanation

(a) Balmer series: The Balmer series is the first series identified in the spectrum of hydrogen. It corresponds to transitions in hydrogen atoms that result in the emission or absorption of light in the visible range, particularly the visible light wavelength range. It's like the opening act in the hydrogen spectrum show!(b) Lyman series: The Lyman series is another important series in the hydrogen spectrum, but it's actually the ultraviolet series, not the first one identified in the visible light range. It involves transitions of electrons in hydrogen atoms that emit or absorb ultraviolet light. It's like the high-energy part of the hydrogen spectrum party!(c) Paschen series: The Paschen series is part of the infrared spectrum of hydrogen, not the first one identified in the visible light range. It deals with transitions in hydrogen atoms that emit or absorb infrared light. It's like the cozy, warm corner of the hydrogen spectrum lounge!(d) Brackett series: The Brackett series is also in the infrared spectrum, not the first one identified in the visible light range. It represents transitions in hydrogen atoms that emit or absorb infrared light beyond the Paschen series. It's like the deeper, hidden layers of the hydrogen spectrum mystery!So, the first series identified in the spectrum of hydrogen, specifically in the visible light wavelength range, is the Balmer series!