Concept:
Bharata Natyam is one of the oldest classical dance forms of India. Its structure, techniques, and expressive traditions were influenced by several ancient Tamil literary works. Among them, Shilappadikaram and Manimekhalai are considered highly significant for the development and structuring of Bharata Natyam.
Step 1: Understand the importance of Shilappadikaram.
Shilappadikaram is a famous Tamil epic that contains detailed descriptions of:
• Dance performances
• Musical traditions
• Stage techniques
• Gestures and expressions
It provides valuable information about ancient Tamil dance traditions.
Step 2: Understand the importance of Manimekhalai.
Manimekhalai is another classical Tamil literary work that contributed to:
• Dance aesthetics
• Cultural traditions
• Performance practices
• Artistic expression
Together with Shilappadikaram, it influenced the evolution of Bharata Natyam.
Step 3: Compare with the given options.
Among the given choices:
• Shilappadikaram and Manimekhalai are directly connected with early Tamil dance traditions.
• Tolkappiyam is mainly a grammar text.
• Abhigyana Shakuntalam and Mruchhakatikam are Sanskrit dramas.
• Dasharupaka and Nartana Nirnaya are important texts but not the primary literary sources for structuring Bharata Natyam.
Therefore, the correct answer is:
\[
\boxed{\text{Shilappadikaram and Manimekhalai}}
\]
Hence:
\[
\boxed{\mathrm{(A)}}
\]