A column of height $h$ with a rectangular cross-section of size $a \times 2a$ has a buckling load of $P$. If the cross-section is changed to $0.5 a \times 3a$ and its height changed to 1.5$h$, the buckling load of the redesigned column will be

- $P/12$
- $P/4$
- $P/2$
- $3P/4$