1. Given:

   • Weight on the surface of Earth: $W = 300\,\text{N}$
   • Depth below surface: $d = \dfrac{R}{4}$

2. Gravity inside a uniform spherical Earth:

   For a point at depth $d$ below the surface, the acceleration due to gravity becomes $g_d = g\left(1 - \frac{d}{R}\right)$ where $R$ is the radius of Earth.

3. Substitute $d = \dfrac{R}{4}$: $g_d = g\left(1 - \frac{1}{4}\right) = g\left(\frac{3}{4}\right)$

4. Weight at that depth: Since weight is proportional to $g$, $W_d = W\left(\frac{g_d}{g}\right) = 300 \times \frac{3}{4}$ $W_d = 225\,\text{N}$

5. Option check:

   • A: $75\,\text{N}$ ❌
   • B: $375\,\text{N}$ ❌
   • C: $300\,\text{N}$ ❌
   • D: $225\,\text{N}$ ✅

Therefore, the body would weigh $225\,\text{N}$ at depth $R/4$ under the surface.