Final answer:
Without seeing the specific sonnet, it's impossible to say whether it is completely in iambic pentameter, partially, or not at all. The correct answer is that we need more information to determine the meter of the sonnet. option c
Step-by-step explanation:
To determine whether a sonnet is in iambic pentameter, we must examine its meter, which should consist of five sets of iambs, or ten syllables, per line, with the pattern of unstressed followed by stressed syllables (da-dum). For example, Shakespeare's Sonnet 18 begins with "Shall I compare thee to a summer's day?" and this line fits the structure of iambic pentameter perfectly. Each line of a sonnet in traditional iambic pentameter should adhere to this rhythmic structure, although poetic licence can lead to variations, such as the occasional line in Shakespeare's works containing an extra, unstressed syllable at the end, as seen in the line "To be or not to be: that is the question" from Hamlet.
In some cases, poets might mix meters and introduce lines with a different rhythmic structure to add variety or emphasis, so without seeing the sonnet in question, it's not possible to categorically state if it is entirely written in iambic pentameter (a), none of it is (b), or only some lines are (c). Therefore, the correct answer is (d) Can't determine without more information.