Final answer:
A motion for a new trial might be granted for reasons including new evidence discovered after the trial, ineffective assistance of counsel, and judicial misconduct. Dissatisfaction with the verdict is not a valid ground for such a motion.
Step-by-step explanation:
Reasons why a motion for a new trial might be granted typically include situations such as: a) New evidence discovered after the trial, b) Ineffective assistance of counsel, and d) Judicial misconduct. These are considered valid grounds as they can significantly impact the fairness and outcome of the original trial.
Option a refers to situations where new evidence that could not have been obtained with reasonable diligence before or during the trial arises and could alter the verdict. Option b reflects scenarios where the defense attorney's performance fell below an objective standard of reasonableness and thereby prejudiced the defendant. Option d includes instances where a judge may have acted with impropriety or bias affecting the fairness of the trial.
Dissatisfaction with the verdict, option c, is not typically a basis for a new trial because it reflects personal dissatisfaction rather than legal error or infringement upon one's rights.