In a stringed musical instrument, the sound frequency of a particular string can be increased by

Atightening the string.
Bincreasing the string's thickness.
Cloosening the string.
Dlengthening the string.

Verified Answer :

W0lf93

The answer is A: tightening the string. By doing this, the string will become slightly shorter. A shorter string, when plucked or bowed, will produce a higher pitch. The other answers will have different results. Increasing the thickness, loosening the string, and lengthening the string will all cause the pitch to lower.

A. "tightening the string" is the correct answer.