I think it's about using practical common sense and LOGIC, there will never be a Standard day.
If you use answer A, it will mean the wind veers 40 degrees! Where you have read that the wind would be 40 degrees?
Also note the question, "LIKELY" - again does not mean it is an exact answer, but you need take the answer most likely closest to what you have read and learnt.
The wind speed you chose 40 kts, which is more then 50% of 25kts, so with what logic would you round it up, when your calculations should be 50%, 40 kts would be 62.5%!
The closest to standard would be the most likely outcome!