The correct answer of the given question above would be the second option. A noun clause is a dependent clause that functions as a noun and is usually introduced by the words that, how, whatever, what, when, where, whether, which, whichever, who, whoever, whom, whomever and why.┬аTherefore, the answer that identifies the noun clause is this:┬аHow the Aztecs made their astronomical calculations.┬а
