Final answer:
The factor that did not help the British win the French and Indian War was a famine in mainland Europe. Key to their victory were strengths such as the robust British navy, increased Parliamentary support, and effective changes in military leadership. The correct option is C. a famine in mainland europe
Step-by-step explanation:
The factor that did not help the British win the French and Indian War was C. a famine in mainland Europe. The strengths that contributed to the British victory included the strength of the British navy, increased support from parliament, and changes in military leadership. The famine in Europe was not directly related to the win for the British in the French and Indian War, which was part of the wider Seven Years' War.
The successes of the British during the conflict can be attributed to a combination of military and financial strategies such as the robustness of the British fleet, Parliamentary backing which ensured sufficient funding, and strategic leadership that proved more effective on the battlefield. These factors, alongside the exhaustion of the French forces and resources, paved the way for the British triumph. However, the famine in Europe did not play a significant role in the context of the war.The correct option is C. a famine in mainland europe