Select the number from among the given options that can replace the question mark (?) in the following series.

10, 18, 42, 114, 330, ?

Given: ​10, 18, 42, 114, 330, ?

Logic: Multiply the difference between the two terms by 3 to get the difference between the next two terms.

10 + 8 = 18

18 + (8 $$\times$$ 3) = 18 + 24 = 42

42 + (24 $$\times$$ 3) = 42 + 72 = 114

114 + (72 $$\times$$ 3) = 114 + 216 = 330

Similarly, 330 + (216 $$\times$$ 3) = 330 + 648 = 978​

So, the missing term is 978.

Thus, the correct answer is (a).