Is risky to answer 1 optional q. first before Question 1?

So long as you have a time budget and you strictly keep to it it’s not too risky at all.

Have a look at this advice on the ACCA website https://www.accaglobal.com/ie/en/student/exam-support-resources/professional-exams-study-resources/p1/technical-articles/tackling-exams.html

I’d say do Q1 first personally spend 20 mins reading it and underlining stuff relating to the requirement and noting them on the side of the paper. Then give yourself 1.5 minutes per mark to answer.

You should have Q1 done in 95 mins from which you then go on to do Section B in another 95 mins. Spend the first 5 mins of the exam picking the section B Qs you will do and writing down the time to spend on each question beside the marks.

This is just advice from me of course. If you have your own plan, go wild.

But trust me you’ll need more then just 15 minutes to read the Scenario for the three questions with enough care and detail.