It is the set of rules, principles, and processes that govern the structure of sentences in a given language, specifically word order and punctuation. The term syntax<span> is also used to refer to the study of such principles and processes.</span>
<span>The Industrial Revolution brought about many changes in terms of economic activity. The good changes were that Industries grew and commerce and trade expanded. Population grew and cities started to rise. Living standards of the people improved due to the increase of wealth giving them access to greater comforts. There was also division of labor making production more efficient. There were also bad changes brought by the Industrial Revolution such as the destruction of small businesses who could not compete with large industries.</span>
.The only sentence that contains a parallel structure is option B. Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal
Options A,C and D are not ´parallel structures because they do not carry the same tense
Parallel structure means that the items included in a list must be in the same form, in this case all main verbs are in the past simple
