Rodrigo "Digong" Duterte, known for his tough stance on crime, emerged as the winner in the 2016 presidential elections of which of the following countries?

Introduction / Context:
This question is from international current affairs and political leaders. Rodrigo "Digong" Duterte is a prominent political figure who gained global attention due to his controversial policies on crime and drugs. Recognising the country where he became president helps in understanding contemporary political developments in Asia.

Given Data / Assumptions:

• The leader mentioned is Rodrigo "Digong" Duterte.
• The event is the 2016 presidential elections.
• The options are different countries: Mexico, the Philippines, Spain, Singapore and Indonesia.
• Only one of these countries elected Duterte as president in 2016.

Concept / Approach:
Rodrigo Duterte served as mayor of Davao City before contesting the presidential elections in the Philippines. In 2016, he won and became the President of the Republic of the Philippines. His strongman style and controversial anti drug campaign were widely covered in international media. None of the other listed countries have a political leader named Duterte who became president in 2016.

Step-by-Step Solution:
Step 1: Recall that Rodrigo Duterte is associated with the Southeast Asian country of the Philippines. Step 2: Remember that he won the presidential election there in 2016. Step 3: Examine the options and identify "The Philippines" as one of the choices. Step 4: Confirm that Mexico, Spain, Singapore and Indonesia have their own distinct leaders and did not elect Duterte. Step 5: Select "The Philippines" as the correct answer.

Verification / Alternative check:
International news reports from 2016 widely covered Duterte's victory and his subsequent policies as President of the Philippines. General knowledge yearbooks also include entries on the leadership change in the Philippines, clearly listing him as president of that country. This consistent association across multiple sources confirms that the Philippines is the correct country among the options.

Why Other Options Are Wrong:
Mexico elected its own presidents with Spanish or Latin American names, but none named Rodrigo Duterte, and the political context is different.
Spain is a European constitutional monarchy with a different political leadership structure and has no president named Duterte.
Singapore has its own president and a long serving prime minister, and Duterte has no political role there.
Indonesia is another Southeast Asian country but its presidents, such as Joko Widodo, are distinct from Duterte and represent a different national context.

Common Pitfalls:
Sometimes students mix up leaders from different countries in Asia and Latin America because of superficial similarities in issues like crime and drugs. Another pitfall is to confuse the Philippines with other island nations in the region. To avoid this, it is important to build clear mental associations: Duterte with the Philippines, Jokowi with Indonesia, and so on. Revising a simple table of major world leaders and their countries is an effective way to reduce such confusion.

Final Answer:
Rodrigo "Digong" Duterte won the 2016 presidential elections in the Philippines.