Which sequence is correct in the life cycle of alternation of generations?

Adrought killed all the plants in an agricultural farmland. gradually, due to wind and some birds for. nearby areas, new plants started sprouting l. what stage of succession was taking place in the farmland? a) competition b) nudation c) ecesis d) reaction e) migration

This is a biological reaction due to a stimulus. i need this quickly !

What is any method of measuring the age of an object or event in years, such as using atomic half-life?