Question

Which is / are true regarding ecosystem?
$A$. self sufficient unit
$B$. cyclic exchange of materials between living beings and environment
$C$. only requirement is input of energy
$D$. characterized by a major vegetation type

• A. $A,C$
• B. $A,D$
• C. $A,B,C$
• D. $A,B,C,D$

Answer 1

Answer: (C)

Correct answer is (c) $A,B,C$