According to tradition, 'Ratnakar' was the earlier name of which sage, the author of the Ramayana?

According to a popular legend, the sage Valmiki, the author of the Ramayana, was earlier a robber named Ratnakar.

The legend of Ratnakar:

• Ratnakar is said to have robbed travellers in the forest to support his family.
• One day, he tried to rob the sage Narada (or, in some versions, the seven sages).
• Narada asked him whether his family would share the burden of his sins.
• When his family refused, Ratnakar realised his mistake and asked Narada for guidance.
• Narada taught him to chant the name of Rama.
• Ratnakar meditated for so long that an anthill ("valmika") grew over his body; when he emerged from it, he came to be called "Valmiki".
• This legend is found in later texts and folk traditions, not in the Ramayana itself.

About Valmiki and the Ramayana:

• Valmiki is called the "Adi Kavi" (first poet) of Sanskrit literature, and the Ramayana is called the "Adi Kavya" (first poem).
• According to tradition, he composed the first verse ("shloka") when he saw a hunter kill one of a pair of birds (krauncha birds), and felt deep sorrow ("shoka").
• The Ramayana has about 24,000 verses, divided into 7 kandas (books): Bala, Ayodhya, Aranya, Kishkindha, Sundara, Yuddha and Uttara.
• In the Ramayana itself, Valmiki gives shelter to Sita in his hermitage, where her sons Lava and Kusha are born and grow up.

Valmiki Jayanti:

It is celebrated on the full moon day of the month of Ashvin.

Other versions of the Ramayana:

• "Ramcharitmanas" in Awadhi, by Tulsidas.
• "Kamba Ramayanam" in Tamil, by Kambar.
• "Krittivasi Ramayan" in Bengali, by Krittibas Ojha.
• "Ranganatha Ramayanam" in Telugu.

Why not the other options?

• ✗Vyasa is the traditional author of the Mahabharata.
• ✗Vishvamitra was a Vedic sage and the teacher of Rama.
• ✗Agastya was a sage associated with south India.