Question

Which of these lines is most clearly an event leading to conflict?

Marya decided she needed a prettier shirt.
Kristen wrote down a new routine for her dance group.
La'ron gained a better understanding of math every time he studied.
Judy was a better dancer than Casey and spent an hour showing off.

Answer 1

Judy was a better dancer than Casey and spent an hour showing off. would be your answer 
hope this helps 

Answer 2

The last sentence. Bragging and showing off leads to conflict all the time.