The United Nations declared the period from 2005 to 2015 as the International Decade for which theme?

Introduction / Context:
The United Nations sometimes announces theme based decades to maintain long term focus on critical issues. One of the most important such initiatives in the early twenty first century was the International Decade for Action known as the Water for Life Decade from 2005 to 2015. For exam aspirants, this question checks whether they can correctly match the decade 2005 to 2015 with the right UN theme related to water and sanitation.

Given Data / Assumptions:

• The period under consideration is from 2005 to 2015.
• The question asks which named decade declared by the United Nations corresponds to this period.
• Options list Water for Life Decade and several other decade themes.
• We assume the candidate is expected to recall the official name of the decade focused on water and its years.

Concept / Approach:
In 2003 the United Nations General Assembly proclaimed 2005 to 2015 as the International Decade for Action with the slogan Water for Life. The aim was to promote international efforts toward meeting water related goals and to improve access to safe drinking water and sanitation. Thus, when the years 2005 to 2015 appear in a question, they should immediately bring to mind the phrase Water for Life Decade rather than other unrelated themes. This is a pure factual recall question based on mapping years to UN initiatives.

Step-by-Step Solution:
Step 1: Identify the years given in the question, which run from 2005 to 2015. Step 2: Recall that the United Nations linked this exact period to an action oriented decade focused on water and sanitation. Step 3: Remember the official title International Decade for Action, Water for Life, commonly shortened in exam notes as Water for Life Decade. Step 4: Look through the options and find the one that refers directly to the Water for Life Decade. Step 5: Select option A, Water for Life Decade, as it correctly matches the UN declared decade from 2005 to 2015.

Verification / Alternative check:
This fact can be verified in United Nations documents, environment and water resource management chapters of geography books, and standard current affairs compendiums. Many exam oriented notes explicitly mention that 2005 to 2015 was declared as the Water for Life Decade by the United Nations to push global progress on Millennium Development Goals related to water. Cross checking with at least one authentic UN or UNESCO source further strengthens confidence in this answer.

Why Other Options Are Wrong:
Option B, Bone and Joint Decade, refers to initiatives in the health sector and does not correspond to the 2005 to 2015 UN water action decade.
Option C, Second International Decade for the Eradication of Colonialism, concerns political decolonisation and follows a different timeline, so it is not applicable here.
Option D, International Decade for Natural Disaster Reduction, relates to the period 1990 to 2000, not 2005 to 2015, and therefore cannot be the correct answer.

Common Pitfalls:
A frequent mistake is to mix up the Natural Disaster Reduction Decade of the nineteen nineties with the Water for Life Decade of the two thousands. Another pitfall is to assume that any decade label mentioning action must be about disasters or health, ignoring the role of water in development. To avoid such confusion, students should build a small table of major UN decades, their themes, and their time spans. Associating water with 2005 to 2015 and disasters with 1990 to 2000 is an effective memory trick.

Final Answer:
The United Nations declared the period from 2005 to 2015 as the Water for Life Decade.