$\begin{array}{l}\text{Here, cost of 8 kg of apples}\\ \\ =\frac{450}{5}\times 8=Rs750\\ \\ \text{Here, cost of 8 kg of apples}\\ \\ =\frac{4320}{12}\times 8\\ \\ =Rs2880\\ \\ \text{Cost of 8 kg of oranges}\\ \\ =\frac{240}{4}\times 8\\ \\ =Rs480\\ \\ \therefore \text{Total cost=Rs (720 + 2880 + 480)}\\ \text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}= Rs 4080}\end{array}$

Hence, option C is correct.