Volume of cone = Volume of two spherical scoops
$$\frac{1}{3}\pi r^2 h = 2 \times \frac{4}{3}\pi \left(\frac{r}{2}\right)^3 = 2 \times \frac{4}{3}\pi \cdot \frac{r^3}{8} = \frac{\pi r^3}{3}$$
$$\frac{1}{3}\pi r^2 h = \frac{\pi r^3}{3} \implies h = r \implies h : 2r = 1 : 2$$
Answer: B) 1 : 2
Set volume of cone equal to total volume of the two scoops. Each scoop has radius $r/2$, so its volume is $\frac{4}{3}\pi(r/2)^3 = \frac{\pi r^3}{6}$; two scoops give $\frac{\pi r^3}{3}$. Equate with $\frac{1}{3}\pi r^2 h$ to get $h = r$, so $h:2r = r:2r = 1:2$.