Select the number that will come next in the following series.

2, 3, 6, 18, 108, 1944, ?

Given: 2, 3, 6, 18, 108, 1944,  ?

Logic: Each term in the series is the product of the previous term and the next term:

2 × 3 = 6

3 × 6 = 18

6 × 18 = 108

18 × 108 = 1944

108 × 1944 = 209952

So, the next number in the series is 209952.

Thus, the correct option is (a) 209952.