In which sentence does the underlined adverb clause modify an infinitive?

We wanted to visit the museum while it was featuring a traveling exhibit about the Titanic.

In the Northern Atlantic, where the Titanic sank, large icebergs are common during cold months.

Although the Titanic sank to the ocean floor, explorers recovered some artifacts from the wreck.

We wanted to visit the museum while it was featuring a traveling exhibit about the Titanic.