Step 1: Understanding the Concept:
The question asks for the correct chronological order of specific items within the traditional Bharatanatyam repertoire, known as the 'margam'.
Step 2: Detailed Explanation:
The standard sequence of a full Bharatanatyam recital progresses from simple to complex, and from pure dance to expressive dance and back. The order of the given items is:
1. (B) Alarippu: An invocatory piece of pure dance, meaning 'flowering bud'. It is the opening item.
2. (A) Shabdam: After Alarippu and Jatiswaram (not listed), this is the first item to introduce abhinaya (expression) with lyrics.
3. (D) Varnam: The centerpiece and longest item of the recital, combining pure dance (Nritta) and expressive dance (Nritya) in complex patterns.
4. (C) Tillana: The concluding item, a joyous and fast-paced pure dance piece with intricate rhythmic patterns.
Thus, the correct sequence is B, A, D, C.
Step 3: Final Answer:
The correct sequence of the items is Alaripu, Shabdam, Varnam, and Tillana.