It's the complete predicate.
The summary of this passage would be more clear if it included the detail that there was a dead virus living inside the monkey. This would make it seem far less random that there is a sudden mention of a monkey without context.
The central idea should also include the phrase "and spread throughout the human species" so that the idea of <em>why</em> a virus coming alive would be scary.
Answer:
It creates surprise since both women find out that they are engaged to a different man who called himself Earnest Worthing.
Explanation:
When the two women finally realize that they had been dating men with different identities who called themselves Earnest Worthing, they are surprised. Surprise is a state of shock because an event or fact is unexpected.
The knowledge that what they knew as true was not really true must have been a source of shock and surprise to the two ladies.
