GAUSS8 2001 Problem 12

Past Contests GAUSS8 2001
, ,
1

A prime number is called a “Superprime” if doubling it, and then subtracting 1, results in another prime number. The number of Superprimes less than 15 is

Answer Choices
A. 2
B. 3
C. 4
D. 5
E. 6