Blank verse rather than a conventional alliterative meter is the aspect of robert frost's poetry that breaks from tradition.
As opposed to many poets who used alliterative meters, Robert Frost, developed his own new form of poetry without alliterative meter.
Robert Lee Frost was an American poet. His work was firstly published in England before it was published in America. Frost was noted for his realistic pictures of rural life and his command of American colloquial speech. He used to write about settings from rural life in New England in the early twentieth century, in order to examine both complex social and philosophical themes.
his structure " the death of the hired man"
his subject matter
The answer is “his subject matter”