What are the correct options?
Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting
a) The amplitude of the sound
b) The frequency of the sitar string with the frequency of other musical instruments
c) The intensity of sound
d) The loudness of sound

The correct answer is option B
Adjusting the frequency of the sitar string with the frequency of other instruments in orchestra is achieved by adjusting the tension and plunk of the string on a sitar.

A sitar can have 18 – 21 strings. About eight of these strings are run over a curve frets and the remaining strings are known as sympathetic strings. The sympathetic strings are tuned to the notes being played. The strings are tuned by tuning pegs and the main strings can be fined tuned by sliding a bead threaded on each string below the bridge.
Hope this helps.

The correct answer to this question is B. A sitar is an instrument that has a long, broad, fretted neck and a gourd-shaped body. It can have 18, 19, 20, or 21 strings. Up to 6 or 7 of the strings run over curved or rasied frets. The remainder of the strings are what are caled sympathetic strings that run underneath the frets.

Chords are not played on a sitar, but rather melodies on two of the strings, while the other strings are tuned to the chord of "raga." When a sitarist tries to adjust the tension and pluck the strings suitably, they are adjusting the frequency of the sitar string with the frequency of the other musical instruments in the orchestra.