The National Council for Curriculum and Assessment, which writes the curriculum Ghanaian schools teach and evaluates the textbooks used to teach it.
It matters to parents for one reason. NaCCA maintains a list of approved textbooks, and a school is meant to select from it. A book that is not on the list has not been through curriculum evaluation, and a school insisting on one is either exercising a judgement it should be able to explain or selling you something.
Ask which books on the list the school has chosen, and why. A school that cannot answer is worth a second look.