Question

Choose the answer that identifies the noun clause. how the aztecs made their astronomical calculations is the subject of my next paper. question 1 options: how the aztecs how the aztecs made their astronomical calculations how the aztecs made their astronomical calculations is the subject of my next paper

Answer 1

The noun clause is how the Aztecs made their astronomical calculations.
Just invert the whole sentence - The subject of my next paper is how the Aztecs made their astronomical calculations.
The whole clause is used as the direct object.