Answer:
840 ( D )
Step-by-step explanation:
GIVEN DIGITS : 1,2,3,4,5,6,7,8
Number of odd numbers = 4
Number of even numbers = 4
therefore the number of odd numbers with 4 different digits can be formed by the same way the number of even numbers ( without repetition )
Hence the number of ways odd numbers with 4 different digits = Total number of ways of forming 4 digit numbers / 2
8*7*6*5 = 1680 / 2 = 840 ways