Answer:
False.
Step-by-step explanation:
Cohesion is the term that justifies the invalidation of an act, because that act has or was performed on illegal grounds. A testament cannot be an invalid claiming coercion, even if the person who issued it has dementia or another problem that impedes their abilities.
A testament represents an individual's last will and shows what he wants to happen after his death. The will is a legal document and valid in any situation.