Which of the following represents a phrase match keyword?

A phrase match keyword is enclosed in quotation marks, which signals to a search engine that the keywords must appear in that exact order, although they may be surrounded by additional words. For example, "smart tv" will return results that include that precise phrase, such as "buy a smart tv" or "the best smart tv," allowing for variations in the surrounding text but keeping the central concept intact.

In comparison, square brackets, like in the second option, denote exact match keywords, where only searches for "smart tv" will trigger results and no additional words are allowed. The third choice, which is without any formatting, represents a broad match keyword, meaning it may return a wider variety of search terms including related phrases. Lastly, the fourth option, using a hyphen, signifies a different term entirely which may not align with the intended keywords.

Therefore, the option indicating "smart tv" in quotation marks accurately defines a phrase match keyword as it restricts the search to that exact sequence while allowing for flexibility in the search context.