Which is correct?

" At 3,916 meters high, Mount Erciyes is the highest mountain in central Anatolia. It's is considered to be an extension of the Taurus Mountains to the south and is generally regarded as the highest peak of this mountain range. The volcano is heavily eroded, but may have erupted as recently as 253 BC, as an eruption of this volcano is believed by some people to be depicted on coins from around that time. The geographer Strabo, who lived from 64 BC to 24 AD, wrote that the summit of Erciyes was never free from snow. He was also told by the few people who reached its top that they had been able to see the Black Sea to the north and the Mediterranean Sea to the south on clear days."

We can conclude from the passage that Mount Erciyes...................
A) was first written about in 253 BC
B) is thought to have erupted about two and a half centuries ago.
C) was climbed by Strabo
D) is not as large as it once was
E) is closer to the Black Sea than the Mediterranean Sea

I said B but the correct answer is D. I couldn't understand why it is D. Can you explain it?