Due to increased weapon and missile launching missions of North Korea, which country launched a spy satellite to monitor North Korean activities?

Introduction / Context:
This question relates to international security and defence related current affairs. North Korea has carried out multiple missile and nuclear tests, creating concern in the East Asian region. Neighbouring countries and global powers have responded with measures such as deploying missile defence systems and launching spy satellites. The question asks which specific country launched a spy satellite to monitor North Korean weapon activities.

Given Data / Assumptions:

• North Korea is conducting increased weapon and missile launch missions.
• A neighbouring or concerned country launched a spy satellite for monitoring.
• The options are South Korea, USA, China and Japan.

Concept / Approach:
Japan has repeatedly launched reconnaissance satellites to monitor developments in North Korea, particularly its ballistic missile and nuclear programmes. These satellites are often referred to as information gathering satellites. While countries like the United States and South Korea also closely watch North Korea using various means, the specific news item generally highlighted Japan as the country launching a dedicated spy satellite in response to North Korean tests. Thus, the correct answer is Japan.

Step-by-Step Solution:

Verification / Alternative check:
To verify, you can connect each option to typical responses to North Korean activity. The USA deploys strategic assets and missile defence systems, but the exam question in standard preparation material focuses on the Japanese information gathering satellite launch. South Korea relies more on alliance based intelligence and missile defence. China tends to call for dialogue and stability rather than launching spy satellites specifically targeting North Korea. This pattern of behaviour helps confirm Japan as the correct answer.

Why Other Options Are Wrong:
South Korea: It is directly affected and has defence systems, but the famous satellite launch highlighted in many questions was by Japan.

USA: The United States has global reconnaissance capability, but the specific report associated with this question refers to a Japanese satellite.

China: China is a regional power and neighbour but did not feature in this commonly asked news item as the launcher of a spy satellite dedicated to monitoring North Korea.

Common Pitfalls:
A frequent mistake is to choose the USA simply because it is known for powerful spy satellites, or South Korea because of its direct conflict with North Korea. However, exam questions often focus on news items that highlight new steps taken by countries that earlier did not have such capability at large scale. Remembering that Japan has its own information gathering satellite programme aimed partly at North Korea is the key to avoiding this error.

Final Answer:
The country that launched a spy satellite to monitor North Korean weapon activities is Japan.