Which sentence is an example of chronological structure in "the city without us"?
a. unheated buildings would result in a destructive freeze-thaw cycle.
b. if flooding were to go unchecked, steel support beams in buildings would rust.
c. after 20 years, rusted beams in buildings will cause them to start collapsing.
d. without daily pumping, manhattan's subway tunnels would be flooded.

After 20 years, rusted beams in buildings will cause them to start collapsing  is an example of chronological structure in "The City Without Us"

Explanation:

Chronological order is the sequence in which something occur. It is additionally described as time order. The term chronological originates from pair of  Greek words. "Chronos" indicates time. "Logikos" implies reason or order.

In writing and communication, chronological order is a method of design in which activities or effects are manifested as they happen or transpired in time and can additionally be described as time or linear order. Here in the given options "After 20 years, rusted beams in buildings will cause them to start collapsing" is the sentence which are arranged in something occur.

where is the