The first passenger plane __(5)__ by British Airways and Air France in 1976. ?

The question asks for the correct form of the verb to complete the sentence: "The first passenger plane __(5)__ by British Airways and Air France in 1976." To choose the correct answer from the options provided, it’s essential to consider the context and grammatical structure of the sentence.

Option A, "introduce," is incorrect because it is in the base form of the verb and does not fit in the passive voice structure required here.

Option B, "has been introduced," is in the present perfect passive voice, which is improper since the action occurred in 1976, a specific point in the past.

Option C, "introduces," is in the present tense and hence does not suit the context of a historical event.

Option D, "was introduced," is the correct answer. It uses the past simple passive voice, indicating that the action (introduction of the passenger plane) occurred in the past (1976), without specifying the doer of the action, which aligns perfectly with the passive structure.

Thus, the correct and most appropriate completion is: "The first passenger plane was introduced by British Airways and Air France in 1976." This construction accurately conveys that the introduction happened in the past and highlights the significance of the event.