The correct option is B LCM
LCM stands for Least Common Multiple.
That is, the smallet common multiple of two or more numbers is their LCM.
For example:
Multiples of 2 are 2, 4, 6, 8, 10, 12...
Multiples of 4 are 4, 8, 12...
Here, common multiples of 2 and 4 are 4, 8, 12...
∴ LCM of 2 and 4 is 4.