The question is not that the end of the world

Some psychologists and educators were adamant about the teaching procedures used at institutions of higher learning.

X and Y were inflexible

For example, the renowned behaviorist B. F. Skinner believed that those colleges set up to train teachers should (i) _______ change their training philosophy, or else be (ii) _______

Skinner believed - in the light of the previous sentence - that the colleges that train the teachers should change and having a shift in their behavior. Therefore, A is completely off. Has no sense

They must change dramatically or drastically their line of teaching or training philosophy I.E They should teach to the teaching staff of being more flexible, teaching the students

OR else be wiped out. abolished

I.E Or you change or we will nuke you

Hope this helps

PS: the real way to score well on the GRE (my philosophy) is not vocab or a fancy strategy but understand what you read

My new motto is Every word counts - count every word!

Regards