In a guitar, two strings, A and B made of some material are slightly out of tune and produce beats of frequency 6Hz. When tension in B is slightly decreased, the beat frequency increases to7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be:
Option: 1 523 Hz
Option: 2 524 Hz
Option: 3 536 Hz
Option: 4 537 Hz