According to the 2016 Human Development Report published by the United Nations Development Programme (UNDP), what was the Human Development Index rank of the United Kingdom among the countries of the world?

Introduction / Context:
The Human Development Index, or HDI, is a composite measure designed by the United Nations Development Programme to rank countries by their level of human development. It combines indicators related to health, education, and standard of living. Competitive exams frequently ask about the relative position of major countries such as the United Kingdom and Norway in specific years, for example in the 2016 Human Development Report.

Given Data / Assumptions:
- The year referenced is the 2016 Human Development Report.- The country of interest is the United Kingdom.- We are given numerical rank options: 4, 16, 64, and 256.- We assume that the candidate is expected to know or recall the approximate position of highly developed countries.

Concept / Approach:
The HDI ranks countries on a scale from 0 to 1 using three main dimensions: a long and healthy life, access to knowledge, and a decent standard of living. Highly developed countries in Western Europe, North America, and a few other regions occupy the top positions. Norway, Australia, Switzerland, Germany, and similar countries often appear in the first few ranks, while the United Kingdom traditionally falls a little lower, but still inside the top twenty.

Step-by-Step Solution:
Step 1: Recall that Norway generally holds rank 1 in HDI for many years including 2016, while the United Kingdom is not at the very top but still in the very high human development category.Step 2: Eliminate obviously unrealistic values. Rank 256 is not plausible because the number of countries in the HDI ranking is usually around 188 to 190.Step 3: Rank 64 would place the United Kingdom among medium level countries, which is inconsistent with its high level of development.Step 4: Rank 4 would put the United Kingdom extremely close to the top, ahead of many other countries that historically score higher.Step 5: The correct rank in the 2016 Human Development Report is 16 for the United Kingdom, which fits its status as a highly developed but not top ranked nation.

Verification / Alternative Check:
Looking at the 2016 Human Development Report table confirms that the United Kingdom held rank 16 in that year. It is helpful to remember that exam questions often pair information such as Norway at rank 1 and the United Kingdom at rank 16 to test both absolute and comparative understanding of the index.

Why Other Options Are Wrong:
4: Too high and inconsistent with the actual listing; the United Kingdom was not among the top four countries in HDI in 2016.64: This would suggest a moderate development level, which is incompatible with the United Kingdoms advanced economy and social indicators.256: This number greatly exceeds the number of countries actually ranked and is clearly incorrect.

Common Pitfalls:
Students sometimes confuse GDP rankings with HDI rankings and assume that a large economy automatically appears in the top five on HDI. Another trap is to memorise only which country was number one and forget the approximate positions of other important countries. To prepare effectively, it is useful to recall a small group of key ranks, such as where Norway, Switzerland, Germany, the United Kingdom, and India are placed in a given report year.

Final Answer:
16 was the Human Development Index rank of the United Kingdom in the 2016 UNDP Human Development Report.