Who is the speaker if this poem?

a. a poet

b. a young a child

c. an outside narrator

d. a child of the future

i dont understand since there are some options im choosing between

come, let us plant the apple-tree.
cleave the tough greensward with the spade;
wide let its hollow bed be made;
there gently lay the roots, and there
sift the dark mould with kindly care,
and press it o’er them tenderly,
as, round the sleeping infant’s feet,
we softly fold the cradle sheet;
so plant we the apple-tree.

what plant we in this apple-tree?
buds, which the breath of summer days
shall lengthen into leafy sprays;
boughs where the thrush, with crimson breast,
shall haunt and sing and hide her nest;
we plant, upon the sunny lea,
a shadow for the noontide hour,
a shelter from the summer shower,
when we plant the apple-tree.

what plant we in this apple-tree?
sweets for a hundred flowery springs
to load the may-wind’s restless wings,
when, from the orchard row, he pours
its fragrance through our open doors;
a world of blossoms for the bee,
flowers for the sick girl’s silent room,
for the glad infant sprigs of bloom,
we plant with the apple-tree.

what plant we in this apple-tree!
fruits that shall swell in sunny june,
and redden in the august noon,
and drop, when gentle airs come by,
that fan the blue september sky,
while children come, with cries of glee,
and seek them where the fragrant grass
betrays their bed to those who pass,
at the foot of the apple-tree.

and when, above this apple-tree,
the winter stars are quivering bright,
and winds go howling through the night,
girls, whose young eyes o’erflow with mirth,
shall peel its fruit by cottage-hearth,
and guests in prouder homes shall see,
heaped with the grape of cintra’s vine
and golden orange of the line,
the fruit of the apple-tree.

the fruitage of this apple-tree
winds and our flag of stripe and star
shall bear to coasts that lie afar,
where men shall wonder at the view,
and ask in what fair groves they grew;
and sojourners beyond the sea
shall think of childhood’s careless day
and long, long hours of summer play,
in the shade of the apple-tree.

each year shall give this apple-tree
a broader flush of roseate bloom,
a deeper maze of verdurous gloom,
and loosen, when the frost-clouds lower,
the crisp brown leaves in thicker shower;
the years shall come and pass, but we
shall hear no longer, where we lie,
the summer’s songs, the autumn’s sigh,
in the boughs of the apple-tree.

and time shall waste this apple-tree.
oh, when its aged branches throw
thin shadows on the ground below,
shall fraud and force and iron will
oppress the weak and still?
what shall the tasks of mercy be,
amid the toils, the strifes, the tears
of those who live when length of years
is wasting this little apple-tree?

“who planted this old apple-tree? ”
the children of that distant day
thus to some aged man shall say;
and, gazing on its mossy stem,
the gray-haired man shall answer them:
“a poet of the land was he,
born in the rude but good old times;
‘t is said he made some quaint old rhymes
on planting the apple-tree.”