Which of the following statements about Tyrannosaurus rex is correct?

The correct answer is Option (3) → It stood about 20 feet in height and had large dagger-like teeth.

Reptiles of different shapes and sizes ruled the earth for about 200 million years. The land reptiles were the dinosaurs, and the biggest of them was Tyrannosaurus rex. About 65 million years ago (mya) the dinosaurs suddenly disappeared.

Option (1) It was a fish-like reptile. — Incorrect. The fish-like reptiles were the Ichthyosaurs, land reptiles that went back into water about 200 mya. T. rex was a land dinosaur.

Option (2) It was a giant fern-eating dinosaur. — Incorrect. The book describes T. rex with huge, fearsome dagger-like teeth, not as a fern-eater. The giant ferns of that time fell and slowly formed coal deposits.

Option (3) It stood about 20 feet in height and had large dagger-like teeth. — Correct. T. rex was about 20 feet in height and had huge dagger-like teeth.

Option (4) It disappeared around 200 million years ago. — Incorrect. The dinosaurs disappeared about 65 mya. The figure of 200 mya is when some land reptiles went back into water as fish-like reptiles.

NCERT Extract:
A Brief Account of Evolution – “… Some of these land reptiles went back into water to evolve into fish like reptiles probably 200 mya (e.g. Ichthyosaurs). The land reptiles were, of course, the dinosaurs. The biggest of them, i.e., Tyrannosaurus rex was about 20 feet in height and had huge fearsome dagger like teeth. About 65 mya, the dinosaurs suddenly disappeared from the earth.”