This question has two parts. Answer Part A$,$ and then answer Part B$.$

Part A

This sentence is from the passage.

"The trick to Caesarea's longevity was the concrete used to build the harbor." $($Paragraph $3)$

What does the word longevity mean in the sentence?

usefulness to people

contribution to history

toughness that lasts over time

genius that interests scientists

Part B

Which detail from the passage best supports the correct answer from Part A$?$

$1."$a $60-$foot$-$wide entrance for ships" $($Paragraph $2)$

$2.$ "Jackson was then enlisted to investigate" $($Paragraph $8)$