Which of the following numbers are common factors of 16 and 24?

1. List the factors of 16

Factors of $16$: $1, 2, 4, 8, 16$

2. List the factors of 24

Factors of $24$: $1, 2, 3, 4, 6, 8, 12, 24$

3. Identify the common factors and select the correct option

Common factors of $16$ and $24$ are $1, 2, 4, 8$.
Looking at the options:
(1) $8$ and $12$ ($12$ is not a factor of $16$)
(2) $2$ and $3$ ($3$ is not a factor of $16$)
(3) $4$ and $6$ ($6$ is not a factor of $16$)
(4) $4$ and $8$ (Both are common factors)