Answer:
x=1
Step-by-step explanation:
Given function,

Since, the zeroes of a function are those input values for which the function gives the output zero,
So, for the zeroes of f(x),
f(x) = 0

( Adding 6 on both sides )
( Dividing both sides by 3 )
( Taking square of both sides )
( Subtracting 3 from both sides )
Hence, the zero of the given function is, x = 1.
First option is correct.