By the 1920s, dogsleds had for quite some time been the essential methods
of movement for mail, payload and individuals in the immense wild
of Gold country. Late advances in flying machine innovation
anyway were rapidly making air travel a favored
transportation mode in remote The Frozen North and dogsledding
would before long become out of date.
– "Iditarod,"
The Frozen North Open Terrains Data Focuses
C seems about right, considering "I" is a first person phrase
My guess would have to be D
