The Portuguese were the first Europeans to arrive in the vicinity, though no existing documentary evidence confirms their presence off the east coast. Is it possible to build a circumstantial (2) case for Portuguese 'discovery'?
The Author suggests that it is, but, in doing so, one needs to survey the whole history of Portuguese expansion for evidence of possible precedents.
The Dutch made the first recorded sightings of the continent. Why didn't they continue their investigations? Why were three voyages to the Gulf of Carpentaria and the northwestern coastline enough?
On the other side of the continent, why did it take so long for someone to encounter Australia's east coast officially?
And, as successive voyages peeled off slices of open ocean that might have contained part of Terra Australis Incognita, who were these people, who were they there, and what were they doing?
So many questions when one might be inclined to confine the investigations to Jansz, Carstensz, Tasman and Cook, with the Portuguese and Dampier as additions to the basic quartet.
But those six names, their actions and "discoveries" all need to be investigated as well.
So The Author needs to locate, collate and interpret a vast quantity of material that relates to the exploration of Australia before 1788. But old habits die hard, and I'm still writing for an examiner who, strangely enough, has vast gaps in his knowledge.