Assertion: Freud believed that unresolved conflicts during the oral stage of development can have long-term effects on a person's life.

Reason: The oral stage is a critical period where a child's basic feelings about the world are established.

Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.

Freud's assertion that unresolved conflicts during the oral stage of development can have long-term effects is true. The oral stage is when a child's basic feelings about the world are established through the focus on the mouth and oral gratification. Any difficulties or unresolved conflicts during this stage can shape an individual's perception of the world, leading to long-term consequences.