Identify the Formula: Fractional compression ($\frac{\Delta V}{V}$) is related to the change in pressure ($\Delta P$) and compressibility ($k$) by the definition of Bulk Modulus ($B$). Compressibility is the reciprocal of Bulk Modulus ($k = 1/B$). $k = \frac{1}{B} = \frac{\Delta V/V}{\Delta P} \implies \frac{\Delta V}{V} = k \times \Delta P$

Calculate Pressure Change: The pressure at the bottom of the ocean due to the water column is given by hydrostatic pressure formula: $\Delta P = \rho g h$ where $\rho = 10^3\text{ kg/m}^3$, $g \approx 10\text{ m/s}^2$ (or $9.8\text{ m/s}^2$), and $h = 2700\text{ m}$. $\Delta P = 10^3 \times 10 \times 2700 = 2.7 \times 10^7\text{ Pa}$

Calculate Fractional Compression: $\frac{\Delta V}{V} = (45.4 \times 10^{-11}\text{ Pa}^{-1}) \times (2.7 \times 10^7\text{ Pa})$ $\frac{\Delta V}{V} = 122.58 \times 10^{-4}$ $\frac{\Delta V}{V} = 1.2258 \times 10^{-2}$ Rounding to one decimal place matches the option $1.2 \times 10^{-2}$.