Final answer:
The line not written in iambic pentameter is "One foot down, then hop! It’s hot." Iambic pentameter involves a specific pattern of unstressed and stressed syllables, and the mentioned line does not adhere to this structure.
Step-by-step explanation:
Iambic Pentameter in Poetry
The line "When I see birches bend to left and right" is not written in iambic pentameter, which is defined as a poetic meter with each line containing five sets of iambs (unstressed syllable followed by a stressed syllable), amounting to roughly ten syllables. This metric structure is used to craft poems and entire plays, giving them a rhythmic and euphonic quality. For instance, Shakespeare's plays often employed iambic pentameter to differentiate between the classes of characters, indicate literary significance, and create a pleasurable auditory experience. However, writing in this form can be quite challenging since it requires the writer to perform intense linguistic gymnastics to adhere to the strict syllabic and stress patterns, sometimes even leading to the use of inverted syntax, a rearrangement of the word order.
Option D "One foot down, then hop! It’s hot." is not written in iambic pentameter. Instead, it has a more irregular rhythm and fewer syllables than required by iambic pentameter. Shakespeare's sonnets, such as Sonnet 18, demonstrate his skillful use of iambic pentameter with a clear pattern of unstressed and stressed syllables in lines like "Shall I compare thee to a summer's day?"