Q:Given the following passage  "Sanskrit (/ˈsænskrɪt/; Sanskrit: saṃskṛtam [səmskr̩t̪əm] or saṃskṛta, originally saṃskṛtā vāk, "refined speech") is the primary sacred language of Hinduism, a philosophical language in Buddhism, Hinduism, Sikhism and Jainism, and a literary language that was in use as a lingua franca in Greater India. It is a standardised dialect of Old Indo-Aryan, originating as Vedic Sanskrit and tracing its linguistic ancestry back to Proto-Indo-Iranian and Proto-Indo-European. Today it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand. As one of the oldest Indo-European languages for which substantial written documentation exists, Sanskrit holds a prominent position in Indo-European studies.",  answer the following question. Note that the answer is present within the text.  Question: Which of the following is youngest, Proto-Indo-European, Sanskrit or Proto-Indo-Iranian?
A:
Sanskrit