In the following sentence completion question on the "Global Nutrition Report 2016", choose the verb form that best completes the statement "The Global Nutrition Report 2016 once again ____________ India's slow overall progress ..." in standard formal English.

Introduction / Context:
This question is part of a passage completion exercise that discusses the "Global Nutrition Report 2016" and its comments on India progress in tackling chronic malnutrition. In cloze tests, the correct option must fit both grammatically and logically with the surrounding sentences. Here, the focus is on choosing the appropriate verb form to complete "The Global Nutrition Report 2016 once again ____________ India slow overall progress ...". The tense choice should match the usual style of reporting the content of a written document.

Given Data / Assumptions:
- The sentence begins with "The Global Nutrition Report 2016 once again". - The missing verb describes what the report does regarding India slow progress. - The report is a published document that continues to exist in the present. - The options include present, past, and past perfect forms.

Concept / Approach:
In formal English, when referring to the content of books, reports, or research papers, writers commonly use the simple present tense, even if the document was published in the past. This is because the content of the document is still valid and can be read now. Therefore, a sentence such as "The report demonstrates that..." usually appears in simple present. Past or past perfect forms are more often used to narrate specific events that are over, not the continuing existence of a text. The phrase "once again" suggests a repeated pattern of pointing out something, which also fits naturally with the present tense "demonstrates".

Step-by-Step Solution:
Step 1: Consider option a, "demonstrates". This simple present form works well with a subject that is a report whose findings are still applicable. Step 2: Consider option b, "demonstrated". This simple past tense treats the reporting action as finished at a moment in the past, which is less natural when discussing what a report still shows. Step 3: Consider option c, "demonstrated that". This would require a different structure, and the given sentence fragment continues directly with "India slow overall progress", so adding "that" may not match the exact original pattern of the passage. Step 4: Consider option d, "had demonstrated". The past perfect is generally used to refer to an action that was completed before another past action, which is not indicated here. Step 5: Since the standard style in academic writing is to say that a report "demonstrates" some fact, and because the sentence describes what the report once again shows, option a fits both tense and style expectations.

Verification / Alternative check:
To verify, complete the whole segment: "The Global Nutrition Report 2016 once again demonstrates India slow overall progress in addressing chronic malnutrition." This reads smoothly in standard editorial style. Substituting "demonstrated" or "had demonstrated" makes the sentence sound like a historical narrative rather than a general statement about the report content. The presence of "once again" also aligns well with simple present, implying that whenever such a report appears, it demonstrates the same worrying trend.

Why Other Options Are Wrong:
Option b "demonstrated" is less appropriate because it treats the demonstration as a one time past event, not as an ongoing message of a published report. Option c "demonstrated that" requires a different syntactic continuation and does not fit smoothly with the rest of the given sentence pattern. Option d "had demonstrated" is wrong because past perfect is used for sequences of past actions and there is no later past event in the fragment to justify its use.

Common Pitfalls:
Candidates often assume that any mention of a year such as 2016 demands a past tense. However, when texts refer to the content of documents, the simple present is standard. Another mistake is to give extra weight to options that appear slightly longer or more formal sounding, such as "had demonstrated", even if they are structurally unnecessary. The safest strategy is to think about whether the subject is a living action or a still available text and then choose the appropriate tense.

Final Answer:
The correct verb form to complete the sentence is demonstrates.