‘Tirobhava’ in a ‘raga’ is meant for which of the following?

• A. Hiding the main ‘swaroop’ of raga during improvisation by using the swaras of other raga.
• B. Using variety of ‘tanas’ in the presentation.
• C. Using the ‘bol’ of ‘mridangam’ in the composition.
• D. Voice modulation.