Correct option is D
Given:
are prime numbers
Solution:
Checking the options:
1. Putting the values of k = 4
k = 4,
Now k itself is not a prime number hence it is not the answer
2. Putting k =3
k=3
12 is not a prime number
3. Using k = 7
k=7
52 is not a prime number
4. Using k =2
k =2
Hence correct answer is option(d) 2