In transition A, hydrogen atom comes from higher energy state n=∞ to lower energy state n=1. Hence, transition A represents series limit of Lyman series. In transition B, hydrogen atom comes from higher energy state n=5 to lower energy state n=2. Hence, transition B represents 3 rd line of Balmer series. In transition C, hydrogen atom comes from higher energy state n=5 to lower energy state n=3. Hence, transition C represents 2 nd line of Paschen series. Hence, option (d) is correct.