An open organ pipe resonated with frequency ????????1 and 2nd harmonic. Now one end is closed, and the frequency is slowly increased. It resonates with frequency ????????2 and nth harmonic. Then, (a) ???????? = 3, ????????2 = 3 4 ????????1 (b) ???????? = 5, ????????2 = 3 4 ????????1 (c) ???????? = 3, ????????2 = 5 4 ????????1 (d) ???????? = 5, ????????2 = 5 4 ????????1