In Easter 1916 Yeats is questioning whether the transendance of the rebels into a stone that diverts history has too high a cost to pay becasue their hearts have been lost(ie their humanity) this questioning of transendance continues throughout Yeats career and is evident in most of his poems...
If they specify a poem they will always allow room for his other poems because this is a critical study of Yeats, not of one of Yeats' poems. I would say that if they were going to specify a poem it would be either second coming, easter 1916 or mabye (its more unlikely) sailing to Byzantium.
There are quite a few readings out there
Even know its late try and get your hands on
"the poems of W.B. Yeats'
A sourcebook
Edited by Michael O'Neill as I found it really helpful. It has critical history, Early critical reception and Modern criticism.
Response
I don't understand why you people always seem to talk about doing only one or two poems. the meaning of a critical study is that you would basiccally take teh six poems and use parts of them all that are indicative of Yeats career as taken from a certain perspective: ie feminist...
Feminist reading
Well from what I've been taught a feminist could look at Yeats texts and say that he itemises women. In when you are aold a male persona speculates on a female reminiscing about the way men loved her as if that was the only important thing in her life. In Wild Swans the sawns...