Answer:
Mr. Van Daan is caught stealing bread in the Annex. This changes our understanding of the past food shortages in the Annex, as they may have been caused by Mr. Van Daan stealing food for himself, leaving the others without food.
The answer is <u>WRECK</u>.
As a noun, 'decay' is the state of gradual damage or decline in strength, soundness, or prosperity, that is to say, of becoming worse. Similar to the noun 'wreck' that is the state of being damaged, disabled, in ruin or dilapidation.
The other words do not support the meaning of 'decay', because 'colossal' refers to something extremely big, 'bare' is something/someone without any clothes or not covered by anything, and 'round' is something shaped like a ball or circle, or curved.