Rearrange the following four fragments (A), (B), (C), and (D) to construct a grammatically accurate and meaningful sentence. If the sentence is already correct, select 'No rearrangement required'.

one of the most effective of the (A) / Yoga is recognized as (B) / physical and mental well-being (C) / ancient disciplines for (D).

The correct option is BADC.

To construct a grammatically accurate and meaningful sentence, let us analyze each of the given fragments:
(A) "one of the most effective of the"
(B) "Yoga is recognized as"
(C) "physical and mental well-being"
(D) "ancient disciplines for"

1. Start by identifying the main subject and verb of the sentence. Fragment (B) introduces the subject and action: "Yoga is recognized as". This naturally acts as the opening phrase.
2. Following "recognized as", we expect a noun phrase describing what Yoga is recognized to be. Fragment (A) ("one of the most effective of the") connects smoothly to (B), forming: "Yoga is recognized as one of the most effective of the".
3. Next, after "the", we need a plural noun that "one of the most effective of the" modifies. Fragment (D) ("ancient disciplines for") provides this noun phrase. Combining (B), (A), and (D) yields: "Yoga is recognized as one of the most effective of the ancient disciplines for".
4. Finally, the preposition "for" requires an object expressing purpose or benefit. Fragment (C) ("physical and mental well-being") completes the thought logically and grammatically: "physical and mental well-being".

Putting all the fragments together in the sequence B → A → D → C creates the complete and coherent sentence:
"Yoga is recognized as one of the most effective of the ancient disciplines for physical and mental well-being."

Therefore, the correct sequence is BADC.