The answer could be B and C, depending on the subject.
It could be B because in Literacy, you add words inside the bracketts to make the thing you're describing contain even more detail.
It could be C because in Numeracy, you set apart confusing numbers so they are easier to read. For example, 7 ÷ 3 x 4 x 8 could be put as (7 ÷ 3) x (4 x 8)