What is the manner of articulation for the phoneme /b/?

The phoneme /b/ is classified as a voiced bilabial stop due to the specific manner and place of articulation involved in its production.

In terms of manner, a stop (or plosive) involves a complete closure of the vocal tract that temporarily stops the airflow. For /b/, this closure occurs at the lips (bilabial), where both lips come together to obstruct the airflow. When the lips are released, the built-up air pressure creates the sound of the phoneme.

Further, the designation of "voiced" indicates that the vocal cords vibrate during the articulation of /b/. This contrasts with voiceless sounds, where the vocal cords do not vibrate.

The other options present different manners or places of articulation. For instance, a fricative involves a narrow constriction that causes turbulent airflow, which does not apply to /b/. Similarly, alveolar and velar stops involve different places of articulation in the mouth (the alveolar ridge and the soft palate, respectively). However, /b/ specifically requires the bilabial closure essential to its identification as a stop. Thus, the accurate classification of /b/ is as a voiced bilabial stop.