Final answer:
The style and content of seventeenth- and eighteenth-century British literature were influenced by increased literacy, which led to a broader audience and new themes reflective of social mobility and the middle class. So the correct answer is Option C.
Step-by-step explanation:
The change in Great Britain that influenced the style and content of seventeenth- and eighteenth-century literature was C. increased literacy. This period, known as the Enlightenment, saw a significant shift in the demographics of those who were reading and the consequent demand for a variety of literary forms. Despite the fact that literacy rates were climbing rapidly among the urban elite, particularly wealthy merchants and aristocrats, they remained relatively low for those at the lower end of the socioeconomic hierarchy, such as rural artisans, peasants, and tradespeople. Nevertheless, as literacy among the middle class began to rise towards the end of the eighteenth century, helped by the emergence of reading clubs and lending libraries, the content of literature began to reflect the interests and experiences of this broader audience. These social changes influenced dramatists and novelists to write about the themes of social mobility, the rise of the middle class, and the experiences of 'self-made men'.