The correct answer is Option B:

Solution:
Considering the given options.

Option A.   

Option B. 

On Option B:  Considering the given number pattern.

Here, the numbers are decreasing.
So, we first find the rule.

Note that:
30 - 3 = 27
27 - 3 = 24
24 - 3 = 21
21 - 3 = 18

So, the rule is "subtract 3", and this is the required answer.

Hence, the correct counting pattern with the rule ‘subtract three’ is Option B: