Question

Beginning in the fall of 1957.

Answer 1

A. Independent clause

Answer 2

The given statement is an example of a phrase, specifically, a participial phrase. The element that is necessary to complete the sentence is an independent clause. A participial phrase consists of words with the -ing or -en form plus its modifiers. This kind of phrase always functions as an adjective. The phrase "Beginning in the fall of 1957" is describing a certain noun, which is found in the independent clause.