Federalism is preferred for large, diverse countries because it:

Question

Accepted Answer

A. lets locals decide local matters

Federalism lets local governments respond to local needs (language, agriculture, schools) while the centre handles unity-requiring matters.
The cost actually goes up, not down.

Answer

makes the army stronger

Answer

reduces linguistic diversity

Answer

reduces cost of government

Federalism is preferred for large, diverse countries because it:

Keep practising Power Sharing and Federalism