I believe it is A) Input because input costs means the cost of direct material, direct labor, and other overhead items devoted to the production of a good or service.
By the 75th anniversary in 1922, Tribune was enjoying greater influence in the Midwest and found it had outgrown its 17-story home on the corner of dear born and Madison street. <span />
The expansion of railroads created more ways for things such as general goods to be shipped elsewhere to buyers or companies. (Hope this helps a bit, sorry for such a short answer.)