Final answer:
Gamak is the correct ornamentation in singing, as mentioned, which is a technique used in Indian classical music to create a vibrato-like effect for melodic enhancement. The correct answer is option b).
Step-by-step explanation:
The ornamentation in singing that is mentioned in the student's question is gamak. This term reflects a technique often used in Indian classical music that involves a rapid alternation of notes to create a shaking effect, which enhances the expressive quality of the music. It's a key aspect of melodic embellishment in various forms of traditional Indian vocal music, both in Hindustani and Carnatic styles. Ornamentation like gamak is integral to the aesthetic and emotional impact of a performance, offering nuances and depth to the rendition of a piece.