The length of the string of a musical instrument is 90 cm and has a fundamental frequency of 120 Hz. Where should it be pressed to produce fundamental frequency of 180 Hz?

(1) 80 cm

(2) 75 cm

(3) 60 cm

(4) 45 cm

(1) 80 cm

(2) 75 cm

(3) 60 cm

(4) 45 cm