Here,

We have 7 integers, out of which we need 4 digit integer

For the 1st digit we can pick any number from the 7 integers, so no. of possible ways to choose = 7 ways

Similarly

For the 2nd digit, no. of ways = 6 ways

For 3rd, no. of ways = 5 ways

For 4th, no of ways = 4 ways

Therefore, The total number of positive 4-digit integers that can be formed (non repetitive) = (7)(6)(5)(4)


Option C