In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: employees of a certain company are each to receive a unique 8 - digit identification code consisting of the digits 0 , 1 , 2 , 3 , 4 , 5 , 6 , and 7 such that no digit is used more than once in any given code . in valid codes , the second digit in the code is exactly twice the first digit . how many valid codes are there ?
Options: a ) 1220 , b ) 1840 , c ) 2160 , d ) 2480 , e ) 2760
c