Change the following sentence from active to passive voice: "I shall have written the full thesis by December." and select the correct passive form from the given options.

Introduction / Context:
Voice change questions require learners to convert a sentence from active voice to passive voice or vice versa while preserving tense, meaning, and time reference. In the given sentence "I shall have written the full thesis by December.", the subject is the first person singular pronoun "I", and the verb form is in the future perfect tense. The task is to choose the passive construction that correctly represents this future perfect meaning. Mastery of such transformations is essential for accurate formal writing and for understanding varied sentence structures in academic texts.

Given Data / Assumptions:
- Active voice sentence: "I shall have written the full thesis by December." - Subject: I. - Object: the full thesis. - Tense: future perfect, indicated by "shall have written". - The passive form must keep the same time reference "by December".

Concept / Approach:
To change an active sentence in future perfect tense to passive voice, the object of the active sentence becomes the subject of the passive sentence. The verb pattern in future perfect passive is "will have been" or "shall have been" plus past participle of the main verb. Additionally, the agent ("by me") is optional but often included for clarity in exam questions. Therefore, the structure we are looking for is "The full thesis will have been written by me by December." Any option that breaks this pattern by using the wrong auxiliary or an incorrect past form of the verb "write" is unsuitable.

Step-by-Step Solution:
Step 1: Identify the object "the full thesis" in the active sentence; this will become the subject in the passive form. Step 2: Recognise that "shall have written" is future perfect. The corresponding passive auxiliary sequence is "will have been" followed by the past participle "written". Step 3: Place the new subject first: "The full thesis". Step 4: Add the correct verb phrase: "will have been written". Step 5: Add the agent "by me" and retain the time phrase "by December", resulting in "The full thesis will have been written by me by December." Step 6: Compare this with the given options and select option b, which matches exactly.

Verification / Alternative check:
Check each alternative carefully. Option a, "By December I shall have wrote the full thesis.", remains in active voice and also uses the incorrect form "wrote" instead of "written" after "have". Option c, "The full Thesis will be wrote by me by December.", uses "will be" without "have been" and also uses "wrote" instead of the past participle. Option d, "By December the full thesis must have been wrote by me.", changes both the auxiliary ("must have been") and the verb form ("wrote"), altering the original meaning and certainty. Only option b preserves the future perfect passive structure with correct grammar.

Why Other Options Are Wrong:
Option a is wrong because it does not change the voice and also uses "wrote" after "have", which is grammatically incorrect. Option c is wrong because "will be wrote" is not a valid tense form; the correct participle is "written", and the future perfect aspect "will have been" is missing. Option d is wrong because it introduces "must have been", which expresses probability rather than the definite future completion implied by "shall have written", and it also misuses "wrote" instead of "written".

Common Pitfalls:
Learners often confuse "wrote" and "written", forgetting that "written" is the past participle needed after auxiliaries such as "have", "has", "had", or "been". Another common error is ignoring the aspect of the tense; many candidates transform future perfect into simple future or present perfect in the passive. To avoid such mistakes, always identify the exact tense first, then apply a consistent transformation rule for that tense when switching to passive voice.

Final Answer:
The correct passive form of the sentence is The full thesis will have been written by me by December.