Which one of the following is not true for Mahajanapadas regarding the collection of regular taxes?

Which one of the following does not refer to the bow (and arrow) as a weapon of war in ancient India?

Which one of the following rivers in India was not crossed by Alexander and his army?

On the banks of which one of the following rivers was the ancient Mahishmati located?

In which of the following Palaeolithic sites, were tools made of limestone found?

Which one of the following groups of plants was domesticated in the ‘New World’ and introduced into the ‘Old World’?