The correct option is D No change
Let’s examine the sentence: “Since last September Patricia has been working at the convenience store down the road.” The sentence shows that Patricia started her job last year only and is still continuing. To convey this continuity of time, the sentence needs verbs of present perfect continuous tense. The present perfect continuous tense (also known as the present perfect progressive tense) shows that something started in the past and is continuing at the present time. The present perfect continuous is formed using the construction has/have been + the present participle (root + -ing). As the subject, Patricia, is a singular noun, helping verb ‘has been’ would be used here in combination with present participle of work, i.e. ‘working.’ So, the sentence is using correct verbs and does not require any change. Hence, Option A is the correct answer. All the other options would render the sentence grammatically incorrect.