What is the average production of company B (in tonnes) from the year 2006 to the year 2011?

Answer: Option C

Average production of company B from 2006 to 2011
$$=\frac{1}{6}\times \left[\left(\frac{4}{5}\times 750\right)+\left(\frac{7}{8}\times 800\right)+\left(\frac{4}{3}\times 600\right)+\left(\frac{12}{11}\times 550\right)+\left(\frac{13}{14}\times 700\right)+\left(\frac{14}{13}\times 650\right)\right]\text{tonnes}$$
= $$\frac{1}{6}$$ (600 + 700 + 800 + 600 + 650 + 700) tonnes
= $$\frac{4050}{6}$$ tonnes
= 675 tonnes