Explanation:

2, 4, 7, 12, 19, 30, ?
2+2=4
4+3=7
7+5=12
12+7=19
19+11=30
30+13=43
(2, 3, 5, 7, 11, 13) are prime numbers, so we are adding first number with first prime number and second with second prime number and so on.

Hence option 3 is the correct answer.