excerpt from i have a dream
martin luther king, jr.

five score years ago, a great american, in whose symbolic shadow we stand today, signed the emancipation proclamation.

what does the affix tion indicate about the word proclamation in this sentence?
a) the word proclamation is a noun.
b) the word proclamation is a verb.
c) the word proclamation is an adverb.
d) the word proclamation is an adjective.