The next number in the sequence will be 12.
Explanation
The given sequence is: 8, 15, 14, 9, 1, 6, 3
If we express these numbers in words, then we can see that the words are in alphabetical order, like....
Eight, Fifteen, Fourteen, Nine, One, Six, Three
There are two numbers 10 and 12 in the options which starts with letter 'T' , but alphabetically 'Twelve' will be the next number after 'Three'
So, the next number in the sequence will be 12.
