What is the meaning of diction ?

What syllables in "arrived" are stressed/unstressed?

Use morphology and syntax to make grammatical sense of the following sentence (mark all that the ova of all mammals except the monotremes undergo holoblastic segmentation. the -s inflection indicates that monotremes is a plural noun. the suffix -ic indicates that holoblastic is an adjective. the suffix -ation in the word segmentation is a noun-forming suffix denoting a process. the -s inflection indicates that monotremes is a possessive noun.

Which best expresses the irony present in this passage?