Question - Shafts of Light

Prompt: Emily Dickinson's "There's a certain Slant of light'

There's a certain Slant of light,
Winter Afternoons -
That oppresses, like the Heft
Of Cathedral Tunes -

Heavenly Hurt, it gives us -
We can find no scar,
But internal difference,
Where the Meanings, are -

None may teach it - Any -
'Tis the Seal Despair -
An imperial affliction
Sent us of the Air -

When it comes, the Landscape listens -
Shadows - hold their breath -
When it goes, 'tis like the Distance
On the look of Death -

Questions:
The poem's central contradiction is:
A. That something immaterial like light can cause mental pain
B. That something which should bring transcendence also brings pain
C. That the living landscape can so soon become deathly
D. That enlightenment can be a cause of despair


Answering the questions:

I found this one very tricky, as analysis of poems really isn't my forte and this one in particular gives you very little material to work with (unlike, for example, Mr Bleaney).
There are several sites out there that attempt to deconstruct this poem, eg
http://american-poetry.suite101.com/article.cfm/dickinsons_slant_of_light
http://www.americanpoems.com/poets/emilydickinson/10210/comments