The correct answer for the script of the Indus Valley civilization is option 2, which is "Undeciphered." The script used by the Indus Valley civilization, also known as the Harappan Civilization, is yet to be deciphered or fully understood. Archaeologists and linguists have been unable to decode the script`s meaning, resulting in its classification as an undeciphered script. Despite numerous attempts, the complex and unique nature of the script combined with the lack of a bilingual text has made it challenging to decipher. Scholars have not yet been able to link the script to any known language or script of the ancient world. Therefore, it remains a mystery, and much research is still being conducted to understand the language and writing system of the Indus Valley civilization.