From the given options, select the figure of speech (poetic device) used in the expression:

"All three stood still to smile silently".

Alliteration

The figure of speech used in the expression "All three stood still to smile silently" is alliteration.

Alliteration is the repetition of consonant sounds at the beginning of words. In this case, the repetition of the "s" sound in the words "stood," "still," and "smile" creates a sense of smoothness and quietness.

The other answer choices are incorrect. Metaphor is a figure of speech in which one thing is compared to another thing without using the words "like" or "as." Simile is a figure of speech in which two things are compared using the words "like" or "as." Personification is a figure of speech in which inanimate objects are given human qualities. None of these devices are used in the expression "All three stood still to smile silently.".