Among the 8! [permutations of the digits 1, 2, 3..., 8, consider those arrangements which have the following property. If we take any five consecutive positions the product of the digits in these positions is divisible by 5. The number of such arrangements is equal to a. $7!$ b. $2.\left(7!\right)$ c. ${}^7{C}_4$ d. none of these

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