Concept:Transhumance is the seasonal movement of livestock herders between different altitude pastures.
Explanation:In mountainous areas, grasslands at high altitudes are usable only in summer when snow melts.
In winter, herders move their animals to warmer lowland pastures for grazing.
This regular back-and-forth movement of animal rearers is called transhumance.
It is a traditional practice in many mountain regions, not only among Europeans.
It is not related to crop farming or mixed farming.
Answer:A. It is the seasonal migration of animal rearers in mountainous areas