Final answer:
A 14-line poem written in iambic pentameter is called a sonnet, which fits the description given in the question, making option A the correct choice.
Step-by-step explanation:
A lyric poem with a traditional form of 14 lines written in iambic pentameter is known as a sonnet. Famous examples can be found in the works of Shakespeare, known as the Shakespearian sonnet, with a rhyme scheme of ABAB CDCD EFEF GG, and in the Italian or Petrarchan sonnets, written by poets like Frost, containing an octave and a sestet with a rhyme scheme of ABBAABBA for the octave. This form traditionally includes a volta, or turn in thought, often marked by words such as "but" or "yet." Unlike a sonnet, a haiku has just three lines influenced by Japanese poetry, focusing on nature, with a syllable structure of 5-7-5 and is unrhymed. A villanelle has a strict form consisting of five tercets and a final quatrain where the first and third lines of the first stanza repeat. The limerick is a humorous poem of five lines, traditionally with an AABBA rhyme scheme and a specific rhythm. In the context of this question, the only option that fits the 14-line iambic pentameter form is a sonnet, making choice A correct.