Need help with lcm (Least common multiple)

Step-by-step explanation:

You can find the least common multiple of 2 numbers by using prime factorisation to find its index notation.

Example:

6=2×3

9=3^2

So to find the LCM of these to find the LCM of these numbers, you need to take the number with the higher index notation and the remaing factor and multiply them.

Example:

LCM(6,9)=2×3^2

=18

the answer to your question is b.