Place the main-sequence lifetime of each of the following stars in order from shortest to longest.

$\mathbf{c}, \mathbf{e}, \mathbf{f}, \mathbf{b}, \mathbf{d}, \mathbf{a}$

$\mathbf{c}, \mathbf{e}, \mathbf{f}, \mathbf{b}, \mathbf{d}, \mathbf{a}$