Answer
$4a$
Work Step by Step
We start with the given expression: $4ab^0$
The zero as an exponent rule states that for every nonzero number $a$, $a^0=1$.
We use this to simplify to $4a\times1$.
The identity property of multiplication states that the product of any real number and $1$ is the original number.
We use this property to reduce the expression to $4a$.