According to Guinness World Records and international reports in 2018, who was recognised as the oldest living man in the world at that time?

Introduction / Context:
Questions about record holders, especially for titles such as the oldest living man in the world, are common in current affairs and general knowledge examinations. These records are usually based on verifications by recognised organisations such as Guinness World Records and gerontology research groups. This question focuses on the year 2018 and checks whether you remember or have read about the person who held the title of oldest living man in the world at that time.

Given Data / Assumptions:

• The year of interest mentioned in the question is 2018.
• We are asked about the oldest living man, not the oldest woman or the oldest person overall.
• The options include Masazo Nonaka, Francisco Nunez Olivera, Juan Pablo Villalos and Les Colley.
• We assume that the title refers to recognition by Guinness World Records and similar bodies.

Concept / Approach:
The approach is to recall the timeline of record holders around 2018. Francisco Nunez Olivera from Spain was for a time recognised as the oldest living man, but he passed away in January 2018. After his death, Masazo Nonaka from Japan was officially recognised by Guinness World Records as the oldest living man. Therefore, for most of 2018, and especially after the official announcement in April 2018, Masazo Nonaka held this title. The other names provided either held the title in different periods or were not recognised in the same way.

Step-by-Step Solution:
Step 1: Recall that Francisco Nunez Olivera, a Spanish supercentenarian, died in late January 2018. Step 2: After his death, Masazo Nonaka, a Japanese supercentenarian born in 1905, became the oldest living man. Step 3: In April 2018, Guinness World Records officially recognised Masazo Nonaka as the oldest living man, confirming his status for that year. Step 4: Les Colley was an Australian supercentenarian who passed away many years earlier, so he could not be the correct answer for 2018. Step 5: Juan Pablo Villalos is not widely known as a verified record holder in this category. Step 6: Therefore, the correct answer for the year 2018 is Masazo Nonaka.

Verification / Alternative check:
A verification method is to consult archived news reports or the official Guinness World Records announcements for 2018. These clearly state that after the death of Francisco Nunez Olivera, Masazo Nonaka was recognised as the oldest living man. He remained in this position until his own death in early 2019. This cross check aligns with the information summarised in many general knowledge resources.

Why Other Options Are Wrong:
Francisco Nunez Olivera was indeed the oldest living man just before 2018 ended, but he died in January 2018 and therefore could not be the record holder for most of that year. Les Colley was a historic supercentenarian whose record dates to an earlier period and is not connected to 2018. Juan Pablo Villalos is not recognised in standard reference sources as the world record holder for oldest living man in 2018.

As a result, none of these alternatives match the specific time frame and recognition mentioned in the question.

Common Pitfalls:
A common mistake is to confuse the oldest living man for one particular year with the oldest person ever or with people who held the record in earlier years. Another error is to ignore the exact time period and focus only on names that sound familiar. To avoid such confusion, always pay attention to the year given in the question and link it to official announcements made in that period.

Final Answer:
The oldest living man in the world recognised in 2018 was Masazo Nonaka.