Answer
Option $(c)$
Work Step by Step
The $\textit{prime factorization}$ of a number is obtained by writing the number as a product of primes.
To determine the prime factorization of $63$ we write the number as a product of factors and continue the process until all factors are prime numbers.
We start by writing $63$ as a product of two numbers:
$63=3\cdot 21$.
The number $3$ is prime, but $21$ is not. So we write $21=3\cdot 7$:
$63=3\cdot 3\cdot 7$.
Now each factor is a prime number, therefore the prime factorization of $63$ is $3\cdot 3\cdot 7$.
The option $(c)$ has the prime factorization.
