What is the effect of these last two lines from the passage? yet joy i shall them so to see, if any joy in age there be.
a. the last line casts some doubt on the joy the speaker anticipates and describes in the previous lines.
b. the altered word order shows the speaker is anxious about living long enough to see the boys grown up.
c. these last two lines bring the passage to a decisive conclusion that reinforces the theme of the rest of the poem.
d. the altered word order demonstrates that the speaker doubts the boys referred to will make her proud.

i think the answer might compound

wordsworth tends to see nature as 'out there'; a presence which surrounds humans, and contributes to human life, but is different from humans. if you look at a typical wordsworth poem (there was a boy, ye knew him well ye rocks) - wordsworth talks about nature as something that needs to be learned about and understood, nature is different from us.  

if you look at a byron poem (the isles of greece is a good one) - byron looks at nature mainly for what it already means to man. wordsworth will look at a landscape and see the mountains, trees, valleys, and rivers as almost spiritual presences - wordsworth wants to get to know nature.  

byron will look at the same landscape and he will want to know who lives there, what are the villages? are there any farms or mines, is there some history?  

wordsworth looks at nature for what it is; byron is forever asking what it means.  

wordsworth thinks that humans are part of nature; byron thinks that nature is part of being human

in our power to make a world happy - to teach mankind the art of being so - to a character hitherto unknown - and to have, as it were, a new creation intrusted to our hands, are honors that command reflection, and can neither be too highly estimated,

not sure maybe the subject closer to it or subject-verb agreement