First you need to know how many prime numbers are from 1 to 12.
Prime numbers: 2, 3, 5, 7, 11. There are 5 prime numbers.
The probability of getting a prime number would be 5/12.
Vowels from A to J would be A, E, I, so 3 vowels.
The probability of picking a vowel would be 3/10.
The probability of picking both would be 5/12 x 3/10 = 15 /120, which reduces to 1/8.
The answer is B.