The Kyoto Protocol is an international treaty under the United Nations framework that commits participating states to reduce which of the following?

Introduction / Context:
This question checks basic knowledge of international environmental agreements, specifically the Kyoto Protocol. The Kyoto Protocol is often mentioned in discussions of global warming and climate change, so understanding its main objective is important for general studies and environment related topics.

Given Data / Assumptions:

• The question refers to the Kyoto Protocol as an international treaty.
• We need to identify what it commits its member states to reduce.
• The options include poverty, greenhouse gases, nuclear weapons, and agricultural subsidies.

Concept / Approach:
The Kyoto Protocol is linked to the United Nations Framework Convention on Climate Change. Its central goal is to set legally binding targets and timetables for industrialised countries to reduce emissions of greenhouse gases which contribute to global warming. It is not a disarmament treaty and does not deal directly with poverty or agricultural subsidies.

Step-by-Step Solution:
Step 1: Recall that greenhouse gases include carbon dioxide, methane, nitrous oxide and some fluorinated gases, which trap heat in the atmosphere.Step 2: The Kyoto Protocol sets country specific targets to reduce or limit these emissions based on a baseline year, usually 1990.Step 3: Examine the options. Only option B explicitly mentions emissions of greenhouse gases.Step 4: Options A, C and D deal with other policy areas such as poverty, weapons and agriculture that are not the primary focus of the Kyoto Protocol.Step 5: Therefore, the correct answer must be the one that refers to greenhouse gas emission reduction.

Verification / Alternative check:
This can be verified by remembering that the Kyoto Protocol was one of the first major steps in translating climate science into binding international obligations. Subsequent agreements like the Paris Agreement built upon this framework but shifted from binding quantitative targets to nationally determined contributions.

Why Other Options Are Wrong:
Option A is wrong because alleviating poverty is a goal of other programmes, such as those linked to the Millennium Development Goals and Sustainable Development Goals, not the Kyoto Protocol directly.
Option C is wrong because nuclear arms reduction is covered by treaties like the Nuclear Non Proliferation Treaty and various strategic arms reduction agreements, not Kyoto.
Option D is wrong because agricultural subsidy reduction is related to World Trade Organization negotiations, particularly under the Agreement on Agriculture.

Common Pitfalls:
Some learners confuse various international treaties, assuming that any large treaty might deal with multiple global problems at once. It is important to associate Kyoto specifically with climate change and greenhouse gas emissions rather than with general development issues.

Final Answer:
The Kyoto Protocol is an international treaty that commits state parties to reduce emissions of greenhouse gases responsible for climate change.