Given the following balances, what is the most appropriate level of planning materiality for the 30 June 2022 audit of your client? (all amounts are in $'000)

Sales: 2055 (2022); 1849.5 (2021); 1644 (2020)

Profit: 118.3 (2022); 106.47 (2021); 94.64 (2020)

Current assets: 4489 (2022); 4040.1 (2021); 3591.2 (2020)

a.

44.9

b.

20.6

c.

22.4

d.

11.8