Step 1: Understanding the Concept:
This question focuses on the structural organization and textual identification of the Rigveda. The Rigveda is organized in two ways: the Mandala-krama (10 Mandalas) and the Ashtaka-krama (8 Ashtakas). It is also important to recognize the 'Pratika' (opening words) of major Vedic Samhitas.
Step 2: Detailed Explanation:
Let's evaluate each statement:
Statement A: "Agnimile purohitam" is the first mantra.
This is a universally known fact. The Rigveda Samhita (1.1.1) begins with the Agni Sukta, and its first line is: "agnimile purohitam yajnasya devamritvijam | hotaram ratnadhatamam ||". This mantra establishes Agni as the primary priest of the sacrifice. Thus, Statement A is correct.
Statement B: "Ishe tva" is the second mantra.
This is incorrect. "Ishe tva..." is actually the opening mantra of the Yajurveda (specifically the Madhyandina and Kanva Samhitas of the Shukla Yajurveda). The second mantra of the Rigveda continues the praise of Agni within the same sukta ("agnih purvebhirrishibhir..."). Thus, Statement B is incorrect.
Statement C: Rigveda has five thousand mantras.
This is incorrect. The Rigveda is much larger. According to the traditional count (Shaunaka's Anukramani), the Rigveda consists of approximately 10,552 mantras (or Riks). The number 5000 is far too low. Thus, Statement C is incorrect.
Statement D: Rigveda has eight Ashtakas.
This is correct. For the purpose of memorization and study, the Rigveda is divided into eight 'Ashtakas' (literally 'eights'). Each Ashtaka is further divided into eight 'Adhyayas' (chapters), making 64 chapters in total. This system is called the Ashtaka-krama. Thus, Statement D is correct.
Final Conclusion: Since Statements A and D are correct, the answer is option (1). This question tests the candidate's basic textual literacy regarding the Veda—its size, its primary divisions, and its opening verses.
Step 3: Final Answer:
The correct option is (1). Only A and D.