Without warning, as if by serendipity, Lucy's mother appeared behind the door and asked Rosa if she would mind helping serve the hot-dogs since she knew the house so much better than anyone else. All the children at the party were delightful, and of course she liked Lucy the best, with her golden birthday crown, leaving Rosa feeling that she had never been so happy in all her life. But the best was yet to come, for after Lucy blew out the candles, Lucy's mother had asked Rosa to help pass the cake around, and Rosa had enjoyed the task immensely.
what words from this paragraph 10 helps the reader understand the meaning of the word serendipity
A. without meaning
B. Lucy's mother
C. helping serve
D. much better
I need to know now