Photographing ice crystals takes patience > > > sometimes it takes hours to find pictures perfect snowflakes and you must repeat it hundreds of time a if b because c although d but

answer is

B because

if the word is plugged in then the paragraph would seem as if that it is explaining why you need patience to take pictures of snowflakes

the figurative meanings of these lines are questioning the tyger's strength and beauty. the meaning contributes to the overall message of them poem because it is explaining how strong the tyger is.

now just elaborate off of that. : )