I'll be honest, while I found this question to be relatively fair in terms of eliminating the incorrect answers, I found it quite challenging understanding the analogy as well.
The argument says the following:
When we predict future, we tend to make cognitive errors. But this doesn't mean we should stop predicting the future. Likewise, when we look at parallel lines, they appear to converge. But this doesn't mean we should surgically fix this issue.
The analogous ideas are as follows:
Cognitive error = thinking parallel lines converge Predicting future = looking along the parallel lines
Just because cognitive error occurs when predicting, does not mean we should stop trying to predict = if offered to fix issue of seeing incorrect convergence, we shouldn't fix this (i.e. just because you incorrectly perceive the lines, this doesn't mean we should stop seeing it incorrectly).
I hope this helps. Please let me know if you have any other questions!