What type of verse is based on the number and alternation of its stressed and unstressed syllables?

The type of verse that is based on the number and alternation of stressed and unstressed syllables is known as accentual-syllabic verse. This form combines both the accentual aspect, which focuses on the stresses in a line of poetry, and the syllabic aspect, which emphasizes the total count of syllables. This structure is prominent in English poetry, where rhythm is often created through a specific pattern of stressed (accented) and unstressed (unaccented) syllables, enabling poets to create a musical quality and emotional effect in their work. The inclusion of both elements allows for a flexible yet structured form of expression, making it a common choice among poets.

Other forms like accentual verse focus solely on stresses without regard to the total number of syllables, while syllabic verse maintains a set syllable count regardless of stress patterns. Accentuated verse, on the other hand, could imply a general emphasis on accents but lacks the specific structure defined by combining both accentual and syllabic principles. Thus, accentual-syllabic verse stands out as the correct classification for this type of poetic meter.