Select the option that expresses the meaning of the underlined segment.
Partly, it may be a desire to stop emotions in front of strangers.

The correct option is Quell.

Let's analyze the context of the sentence to find the meaning of the underlined word "stop":
"Partly, it may be a desire to stop emotions in front of strangers."

Here, the sentence talks about controlling, suppressing, or putting an end to one's emotions (specifically in a social context where one wants to avoid showing feelings to strangers). We need to find the word among the options that best matches this meaning of suppressing or calming down an internal feeling or emotion:

1. Smash: This means to violently break something into pieces. It does not fit the context of managing or suppressing emotions.
2. Quiet: While "quiet" can mean to make silent or calm, it is less commonly used as a transitive verb for suppressing emotions in this formal context compared to other options.
3. Quell: This means to suppress, put an end to, or extinguish (a rebellion, feeling, or emotion). For example, one can "quell fears" or "quell emotions." This fits the context of suppressing or stopping emotions perfectly.
4. Put out: This is a phrasal verb often used for extinguishing a fire or causing inconvenience. It is not the standard term used for suppressing emotions in front of others.

Therefore, the word Quell is the most appropriate synonym for the underlined segment "stop" in this context.