Answer and explanation: A semicolon can be used mostly in this cases: when we list elements and any of the items contain commas, for example, sentence A: His suitcase held only a few items: a magazine from Kenya; two carefully folded silk handkerchiefs, each with the monogram; and a can of brown shoe polish.
We also use a semicolon to join two independent clauses that are related, for example, sentence B: They were getting ready to make the trip to the island; It was a yearly ritual.
In sentences C and D, we use a colon instead of a semicolon, because a colon is used to introduce an explanation: The first words of her speech were uninspiring: "Um, I seem to have misplaced my notes" and There was only one problem: I was stuck in a cardboard box.