I found this article...
https://www.demorgen.be/nieuws/links-blijven-rijden-op-de-snelweg-wat-zegt-de-wegcode-exact~b27489a7/?referrer=https%3A%2F%2Fwww.google.com%2F

Basically you should chose the lane that best fits your itinirary... so driving on the left just for fun and then all of a sudden turning right 50 meters before a crossing is still considered erroneous behaviour...

I think the nuance in the question/answer is to reflect that basically the answer is 'rather yes than 'definitely no', but still 'yes, you can, but not if it's more elegant to drive on the right because at the next crossing you need to go right anyway...

Question : 12558

Within a built up area you have two lanes in your driving direction. Can you continue to drive in the left lane.

A. Yes, always within built up area
B. Yes, if you want to turn a little further to the left or park to the left

Answer : B

Question : 12555

Within a built up area you have two lanes in your driving direction. Can you continue to drive in the left lane.

A. Yes
B. No

Answer : A

Can someone explain me, why for 12558, answer is B and not A.