Suppose a mutation occurs in an individual animal in a population. What possible outcomes could happen if the mutation had these different effects on the animal?

Question

The picture is a fish in a school where a fish has red stripes while the others don't
These are the three choices I could choose for each scenario.
The mutation will become more common.
The mutation will disappear.
The mutation will remain at a low level
Scenario #1: The mutation results in the organism having more offspring.
Answer: The mutation will remain at a low level

Scenario #2: The mutation creates resistance to a deadly disease.
Answer: The mutation will disappear.

Scenario #3: The mutation results in the organism being less attractive to potential mates.
Answer: The mutation will remain at a low level

Scenario #4: The mutation produces no change in the animal.
Answer: The mutation will become more common.

Please tell me if im right.