In music, a continuous flow at a uniform speed is called

Indian classical music (Hindustani and Carnatic) distinguishes several rhythm-related concepts — the fixed cyclic metre that structures a performance's beats, and a stressed reference beat within that cycle — while poetic metre (chhanda) is a separate, literary concept from Sanskrit/Hindi verse composition. Distinct from all of these is the pace at which a piece is rendered, generally graded as slow, medium, or fast; the question is testing the distinction between these musical and prosodic terms.

The phrase "a continuous flow at a uniform speed" describes exactly this pace dimension, not the cyclic pattern, the reference beat, or the poetic metre. In Indian classical music terminology this pace is called Laya (tempo), graded into vilambit (slow), madhya (medium), and drut (fast) — each maintaining a steady, unbroken flow of beats. This matches the standard definition given in Indian classical music theory (for example, IGNOU's music course material), and the item is a UPTET 2018 Paper 2 general-awareness question testing this exact definition.

• Taal names the fixed rhythmic cycle a piece is set to (for example, the 16-beat Teentaal) — a repeating beat-pattern, not a measure of pace.

• Sam is the first, stressed beat within a taal cycle — a single reference point, not an ongoing pace.

• Chhanda governs Sanskrit/Hindi verse composition — a literary concept defined by a fixed count of syllables and a laghu-guru (light-heavy) pattern, distinct from musical pace.

Because the question asks only about the pace dimension, and only one of the four terms is defined around pace rather than cyclic pattern, beat-position, or poetic metre, the correct term is Laya.