Which of the following is an example of an unvoiced consonant?

An unvoiced consonant is a consonant sound that is produced without the vocal cords vibrating. In the English language, an example of an unvoiced consonant is "c," as in the initial sound of the word "cat." When pronouncing this sound, the airflow is directed through the mouth without engaging the vocal cords, making it unvoiced.

The other options represent voiced consonants, where the vocal cords vibrate during their articulation. For instance, "b" is produced by bringing both lips together and voicing; "g" is a voiced velar consonant made with the back of the tongue against the soft palate, and "d" is also voiced, produced by placing the tip of the tongue against the alveolar ridge and engaging the vocal cords. Understanding the distinction between voiced and unvoiced consonants is fundamental in phonetics and pronunciation.