1. For a planet, acceleration due to gravity at the surface is

$g = \frac{GM}{R^2}$

2. Mass of a spherical planet is

$M = \frac{4}{3}\pi R^3 \rho$

Substitute into the formula for $g$:

$g = \frac{G\left(\frac{4}{3}\pi R^3 \rho\right)}{R^2} = \frac{4}{3}\pi G R \rho$

So,

$g \propto R\rho$

3. Given:

• Radii ratio: $R_A : R_B = 2 : 3$
• Density of A: $3\rho$
• Density of B: $5\rho$

Therefore,

$g_A : g_B = (R_A \rho_A) : (R_B \rho_B)$

$= (2 \cdot 3\rho) : (3 \cdot 5\rho)$

$= 6\rho : 15\rho = 2 : 5$

4. Hence, the correct option is:

$\boxed{2:5}$

So, Option D is correct.