Select the number from among the given options that can replace the question mark (?) in the following series.
3, 18, 63, 198, 603, ?

3,18,63,198,603,?

Let's look at the differences between consecutive terms:

18−3=15

63−18=45

198−63=135

603−198=405

So, the differences between consecutive terms are:

15,45,135,405

45=15×3

135=45×3

405=135×3

It looks like each difference is multiplied by 3.

The next difference will be:

405×3=1215

Now, add 1215 to the last term (603):

603+1215=1818

Thus, the number that replaces the question mark is 1818.

Thus, correct option is (d).