The name, office and starting point belong together.
“First” is the decisive word. All four options name people who really served as Federal Chancellor. The question therefore tests who held the office at the Federal Republic’s beginning, not who ever held it.
The Federal Republic was founded in 1949. Its first federal institutions were established in that year. Adenauer’s election belongs to this founding year; the end of World War II in 1945 is a different point in time.

The other three answers
The three other names belong to later governments.
Kurt Georg Kiesinger
Kurt Georg Kiesinger was Federal Chancellor from 1966 to 1969. Adenauer and Ludwig Erhard had already served before him.
Helmut Schmidt
Helmut Schmidt served from 1974 to 1982. His chancellorship began a quarter of a century after the Federal Republic was founded.
Willy Brandt
Willy Brandt was Federal Chancellor from 1969 to 1974. He was a later officeholder, not the first one in 1949.
“Federal Chancellor” identifies a specific office.
The question concerns the Federal Republic of Germany. It does not refer to earlier German states or other titles such as Reich Chancellor. A head of government of the GDR would not be a suitable answer either.
The Federal Chancellor is elected by the Bundestag. The historical answer Adenauer should therefore not be learned as an example of a direct popular election of the head of government. The office of Federal President remains separate.
Chancellors since 1949 · Federal Chancellery ↗1949: first Federal Chancellor → Konrad Adenauer.
First learn the link between the founding year, office and name. The later terms then help rule out the distractors.
Three words for this question
- der BundeskanzlerFederal Chancellor
- The head of government of the Federal Republic of Germany.
- der Amtsinhaberofficeholder
- The person holding a particular office.
- die Amtszeitterm of office
- The period during which someone holds an office.
