I ended up with A and D - but in the end I decided to pick D!
We know that...
...the new radio has two new features.
...has "record-high" sales figures ("record-high" might imply that sales figures have never been this high)
...the old radio generated more PROFIT in the same amount of time (Revenue-Costs (old) > Revenue-Costs (new))
For the equation to hold,
even if revenues would be same (revenue old shout be smaller than revenue new probably), then Costs (old) have to be smaller than costs (new)
Looking at the answer choices:
A) According to A the new screen led to higher costs -> This would make sense. But we can't really infer that the screen has to be the reason (it could also be another cost position)
D) "Old model cost less" -> this has to be an inference as discussed above (for the equation to hold, the costs (old) have to be smaller than costs (new))
As the inference of D is definitely stronger imo - I choose D
Bunuel What do you think of my reasoning?