How many 4-digit positive integers are there, where each digit is positive, and no 4 adjacent digits are same?	Choose the correct choice from the following
A) 1236  B) 3024  C) 4096  D) 4608  E) 6561
First digit.. 9 posibilities   Second digit, 8 possibilities   third digit, 7 possibilities   Fourth digit, 6 possibilities.   9*8*7*6= 
<gadget id="calculator">9*8*7*6</gadget>
<output>3_024</output>
3024.   3024
<result>B</result>
How many 4-digit positive integers are there, where each digit is positive, and no 4 adjacent digits are same?