If $\mathbf{a}_{\mathbf{1}}, \mathbf{a}_{\mathbf{2}}, \mathbf{a}_{\mathbf{3}}, \ldots$ are in increasing geometric progression such that
$a_{1} + a_{3} + a_{5} = 21$,
$a_{1}a_{3}a_{5} = 64$
then $a_{1} + a_{2} + a_{3}$ is
(A) 7
(B) 10
(C) 12
(D) 15