Question

Which line of poetry is written in iambic pentameter?

Answer 1

When you say "Which ... ", are you saying "Here's a list of choices.
Please select your answer from the list." ?

If so, then there's something definitely missing here.

And since my answer is not restricted to the list of choices you provided,
I get to pick any line of poetry I want to.

                to BE    or NOT    to BE    that IS    the QUES    tion.

This is iambic pentameter.

(The "-tion" kind of hangs off at the end, but hey !  It's Shakespeare. 
Wotta ya gonna do.  You can't tell him anything.)

Answer 2

Iambic pentameter is a type of metric line used in traditional English poetry and verse drama. The term describes the rhythm, or meter, established by the words in that line; rhythm is measured in small groups of syllables called "feet". "Iambic" refers to the type of foot used, here the iamb, which in English indicates an unstressed syllable followed by a stressed syllable.