What are the semicolons doing in this sentence?

Saihou needed a lot of new clothes for summer: swim trunks, flip-flops, and goggles for the pool; a linen shirt; and a straw hat.

(1 point)
Responses

They're separating items in a complex list.
They're separating items in a complex list.

They're uniting closely connected clauses.

They're uniting closely connected clauses.

The semicolons in the given sentence are separating items in a complex list.