Hi! The sentence you gave is a complex sentence. For a sentence to be compound, it should contain multiple subjects or predicate. On the other hand, for it to be complex, a subordinate clause must be present.
We can notice that the clause "that were built under the city" is a clause that cannot stand alone thus this will tell us that the sentence is complex.
ANSWER: D. Complex
There are a lot of steps that Justinian took to revive the Rome glory.
1. He preserved greek and roman culture/works
2. He conquered back many of the lands that Rome once controlled.
3. He was known for building churches, schools, and courts, like ancient Rome did.
4. He created a code of laws called the "Justinian code".
The children have been studying for the test
Answer:

lots of languages ┐( ̄ヘ ̄)┌ my teacher can speak!!!