Does a B grade in Year 10 5.3 maths enable a student to choose Prelim Maths (2 Unit) and Prelim Maths Extension 1 (3 Unit) in Year 11?
The Board of Studies has a list of Band descriptors on this webpage:
https://arc.bostes.nsw.edu.au/go/sc/sc-grading/cpds/#Stage-5-grading
A10, A9, B8, B7, C6...