A piece of bone of an animal from a ruin is found to have ${}^{14}\mathrm{C}$ activity of 12 disintegrations per minute per gm of its carbon content. The ${}^{14}\mathrm{C}$ activity of a living animal is 16 disintegrations per minute per gm. How long ago nearly did the animal die? (Given half life of ${}^{14}\mathrm{C}$ is $\mathrm{t}_{1/2}=5760$ years)\\
(1) 1672 years\\
(2) 2391 years\\
(3) 3291 years\\
(4) 4453 years