Read the excerpt from “The Monkey's Paw.” Mr. White took the paw from his pocket and eyed it dubiously. "I don't know what to wish for, and that's a fact," he said, slowly. "It seems to me I've got all I want."
"If you only cleared the house, you'd be quite happy, wouldn't you?" said Herbert, with his hand on his shoulder. "Well, wish for two hundred pounds, then; that'll just do it."
His father, smiling shamefacedly at his own credulity, held up the talisman, as his son, with a solemn face, somewhat marred by a wink at his mother, sat down at the piano and struck a few impressive chords.
"I wish for two hundred pounds," said the old man distinctly.
A fine crash from the piano greeted the words, interrupted by a shuddering cry from the old man. His wife and son ran toward him.

Which phrase indicates a change in mood within the excerpt?

“struck a few impressive chords”
“smiling shamefacedly at his own credulity”
“a fine crash from the piano”
“interrupted by a shuddering cry”