MHT CET Physics question

When tension 'T' is applied to a sonometer wire of length 'l' it vibrates with the fundamental frequency 'n'. Keeping the setup same, when the tension is increased by 8 N, the fundamental frequency becomes three times the earlier. The initial tension applied to the wire was [MHT-CET 2020]

• (A)2 N
• (B)4 N
• (C)0.5 N
• (D)1 NCorrect