The correct answer is option 'A' - Sabre-toothed cat.

Explanation:
The sabre-toothed cat, also known as Smilodon, is an extinct animal that lived during the Pleistocene epoch, which was from about 2.5 million to 11,000 years ago. It is one of the most well-known extinct animals and is often depicted in popular culture.

Below is a detailed explanation of the given options and why they are either extinct or not:

a) Sabre-toothed cat (Smilodon) - This is the correct answer. Sabre-toothed cats were large, predatory mammals that had long, curved canine teeth. They became extinct at the end of the Pleistocene epoch.

b) Porpoise - Porpoises are still living animals. They are small cetaceans that are closely related to dolphins and whales. They can be found in oceans around the world.

c) Salamander - Salamanders are a group of amphibians that are still alive today. They have a long, slender body and a tail and can be found in various habitats, including forests, ponds, and streams.

d) Tasmanian devil - The Tasmanian devil is a marsupial that is native to the island of Tasmania in Australia. While they have faced population declines and are considered endangered, they are not extinct.

In conclusion, the sabre-toothed cat (Smilodon) is the correct answer as it is an extinct animal that lived during the Pleistocene epoch.