I don't interpret the first one as a possessive noun. I believe it is the subject of the verb, "wishes." However, 3 is right if it is a possessive.
I disagree with your second answer.
_______wishes to become a opera singer.
1. Kate Tomas
2. Kate Tomas'
3. Kate Tomas's
answer:3
The ___ cheers could be heard for blocks.
1. crowds
2. crowd's
3. crowd
answer: 3
5 answers
answer: crowds
No. The cheers belong to the crowd. Crowd's cheers
I think both your answers are wrong here. Cheers could be heard? Whose cheers? And someone wishes, so she is the subject of the sentence, not a possessive.
1.Kate Tomas