You fix the bug in your solution. Your current solution version is 3.1.2.4. 
What will be the version of the solution update?

Answer options:

A.3.2.0.0
B.3.1.2.5
C.3.2.2.4
D.3.1.3.4
E.3.1.3.0

Correct Answer: D 
There are two options for the managed Dataverse solutions updates: To create a patch — a bug fix or some minor solution change
To clone — a major solution update
You can select a solution from the Power Apps portal and click on the three dots for more options. When you choose the Clone menu item, you will see two options: Clone a patch and Clone a solution. 

Every solution has a version number with the following structure: <major>.<minor>.<build>.<revision>. 
The “Clone a patch” controls the last two numbers: <build> and <revision>. The Power Platform automatically increments the build number, e.g., if the basic solution has a 3.1.2.4 version (Number 1), the patch will have by default 3.1.3.4 (Number 2). Users can change the last two numbers only. 

All other options are incorrect. 
For more information about cloning the Dataverse solutions, please visit the below URLs: 

https://docs.microsoft.com/en-us/power-platform/alm/update-solutions-alm
https://carldesouza.com/how-patching-of-solutions-works-in-the-power-platform/