8^2.4 × 2^3.7 ÷ ( 16 )^1.3 = 2^?

Answer: Option B

$$\begin{array}{rl}& \text{Let }{8}^{2.4}\times 2^{3.7}÷{\left(16\right)}^{1.3}=2^x\\ & \text{Then,}{\left(2^3\right)}^{2.4}\times 2^{3.7}÷{\left(2^4\right)}^{1.3}=2^x\\ & \iff 2^{\left(3\times 2.4\right)}\times 2^{3.7}÷2^{\left(4\times 1.3\right)}=2^x\\ & \iff 2^{7.2}\times 2^{3.7}÷2^{5.2}=2^x\\ & \iff 2^x=2^{\left(7.2+3.7-5.2\right)}\\ & \iff 2^x=2^{5.7}\\ & \iff x=5.7\end{array}$$