On His Being Arrived to the Age of Twenty-three
by John Milton

How soon hath Time, the subtle thief of youth,
Stolen on his wing my three and twentieth year!
My hasting days fly on with full career,
But my late spring no bud or blossom shew'th.
Perhaps my semblance might deceive the truth,
That I to manhood am arrived so near,
And inward ripeness doth much less appear,
That some more timely-happy spirits indu'th.
Yet be it less or more, or soon or slow,
It shall be still in strictest measure even
To that same lot, however mean or high,
Toward which Time leads me, and the will of Heaven.
All is, if I have grace to use it so,
As ever in my great Task-master's eye.

Which term describes the first eight lines of "On His Being Arrived to the Age of Twenty-three"?
A. volta B. octave
C. sestet D. quatrain