First off: The main() parameter is spelled wrong:
String not Sting (I like Police too ;-)
Find how many brackets the left value removes from the original declaration. And find out if the value assigned has the same number of brackets.
A. b2[0][1] = b. You are assigning an array of array of bytes (2 brackets) to an array of array of bytes (removed 2 brackets on the left) GOOD
B b[0][0]=b3. You are assigning a byte to a byte (removed 2 brackets). GOOD
C. b2[1][1][0]=b[0][0]. You are assigning a byte (removed 2 brackets) to an array of bytes (removed one.) // WRONG
D. b2[1][2][0]=b. You are assigning an array of array of bytes to an array of bytes (removed one.) // WRONG
E. b2[0][1][0][0]=b[0][0] You are assigning a byte to a byte. // GOOD
F. b2[0][1]=big You are assigning an array of array of bytes (2 brackets) to an array of array of bytes (removed 2 brackets on the left) // GOOD same as A
The most time consuming part is making sure that the bounds of the arrays on both sides are respected.