Answer:
The central idea of the text The Beast of Loch Ness is to claim that possibly there is a creature living in the lakes of Loch Ness.
Step-by-step explanation:
The Beast of Loch Ness is an article written by Lauren Tarshis. The article talks about various creatures, supposedly called monsters by the humans who witnessed them. The author is making a point that through history many people have claimed to see the sea creatures from myth and legend, only to be found true; be it the discovery of the giant squid or the Komodo dragons.
By stating these examples, the author is making a point that those who claimed to have seen a creature in Loch Ness must be true. As many people witnessed that they have seen the creature.
So, the central idea is that possibly there is a creature living in the lakes of Loch Ness.