Answer:
1. A: Why did Michael call so early this morning? B: I have no idea <u>why he did that</u>.
2. A: Where did Yu say the new office is going to be? B: I don't remember <u>where he said the building will be</u>.
3. A: Why did Emily cut her hair? B: I don't know <u>why she would cut them</u>.
4. A: How long is this going to take? B: I'm not sure <u>how long it will be</u>.
5. A: How much is this going to cost? B: I have no idea <u>how much this will cost</u>.
Explanation:
A noun clause is a clause/ phrase that contains a subject and a verb in it. It also functions as a noun in the sentence, more specifically starting with the words such as "how, why, who, where, what, which, whether" etc. among others.
In the given exchanges between person A and person B, the noun clauses for the respective sentences/ exchanges are-
<u><em>1. why he did that.
</em></u>
<u><em>2. where he said the building will be.
</em></u>
<u><em>3. why she would cut them.
</em></u>
<u><em>4. how long it will be.
</em></u>
<u><em>5. how much this will cause.
</em></u>
They all start with the words that are for noun clauses and also have verbs in each of them.