One function, different office titles.
A state government needs political leadership. In most German states, its head is called Minister-President. This concerns a Land, not the federal government.
Berlin uses Governing Mayor and Hamburg First Mayor. In Bremen, the President of the Senate holds the title Mayor. Saying “in every Land” would therefore be inaccurate.

The other three answers
The alternatives are not the usual title for most state government heads.
First Minister
First Minister is not the German title sought here. Do not confuse it with Hamburg’s First Mayor.
Prime Minister
Prime Minister is a familiar international term, but not the usual German title asked for here.
Senator
Senators belong to city-state governments. Senator is not the title sought for most heads of government.
A title does not tell you every detail of an office’s powers.
State constitutions regulate responsibilities and government formation in detail. Identical titles do not mean every procedure is identical across the Länder.
The Federal President is a different office at federal level. The word president alone is not enough to identify a function.
Head of a state government · Political offices ↗Most Länder: Minister-President. Three city-states: mayoral titles.
Always connect an office’s title with its level and function.
Three words for this question
- der MinisterpräsidentMinister-President
- Usual title of a territorial state’s head of government.
- der Stadtstaatcity-state
- A German state with a particular urban structure.
- der Senatsenate
- Here: a city-state’s government.
