Because the question asks "Which of the following is allowed"
b) is allowed, as you are not going outside the 10nm
d) may be allowed, provided certain other things are done (steady track, but this is not mentioned in this answer)
However as d) only states "originating in the zone", it is not as correct as b).
Remember with every CASA exam, it is NOT the right answer you are looking for, it is the MOST CORRECT.
Some questions, especially ones that ask "which is the most important consideration when..." will have more than one answer which is correct, but one is more important, or all the answers are wrong, but one is closer to being right than the others. As Chimbu said, it's all about comprehension.
You gotta love CASA questions....ATPL air law is even trickier....and they claim they don't try to trick you....Bullsh*t!
Totally agree. And ATPL Flight Planning is just as bad.
