Answer:
The given equation is
ax b= 0,
As we see that, it is a linear equation in one variable containing two constant.
So , a≠ 0 [then equation has no meaning.If a=0 , then , which is meaningless]. ∴ a=0 is incorrect.
Similarly , b≠ 0 [ Reason same as above]. ∴b=0 is incorrect.
⇒3 x=0
⇒x=0 is the correct response.
Let me explain by this giving an example
⇒5 x=0
⇒ x=0 but 5≠0
So, x=0 or 3 x=0 is correct response.