official question from 5lb book.

They come only from ETS material. Not only that, MGRE usually is not the best for the GRE verbal part

Here is another reason why

https://youtu.be/f4o10Xtb1xc?t=1934

In contrast to environmental economics, an older field that concerns itself with the monetary valuation of natural resources, the emergent field of ecological economics positions the human economy as a subsystem of natural ecologies, thus _________ environmental economists’ subordination of the natural world.

There is a contrast being built up between environmental economics and ecological economics.

environmental economics = humans assign monetary value to natural resources and thus subordinate the natural world to humans.

ecological economics = human economy is a subsystem of natural ecologies and thus human economy is subordinate to the natural world.

Both are exact opposites of each other. Thus the word for the blank is reversing.

Why not refute?

Refuting means criticising, condemning or denouncing the previous position of natural world being subservient to humans. The ecological economics reverses the position by making the human economy subservient to the natural world. The reversing may also be considered a form of refutation
but there is no explicit refutation of the earlier position.