A diagnosis of mental retardation means that a child

a.can't read or write at a funtional level.
b.needs serious learning support in mental ability and behaviour.
c.has a mental age equal to his or her chronological age.
d.can never funtion in normal society.

it is B.

Your answer is probably what your teacher wants. However, many people with mental retardation do not need help with their behavior. The other answers are definitely wrong.

B. needs serious learning support in mental ability and behavior.

To arrive at this answer, we need to understand what a diagnosis of mental retardation implies. Mental retardation, also known as intellectual disability, is a neurodevelopmental disorder characterized by limitations in intellectual functioning and adaptive behaviors. These limitations typically manifest during childhood and have a significant impact on an individual's daily life.

Option A states that a child with a diagnosis of mental retardation can't read or write at a functional level. While it is true that individuals with intellectual disabilities may face challenges in acquiring literacy skills, this statement is too generalized and may not apply to every case. Some individuals with intellectual disabilities can learn to read and write, albeit at a slower pace and with appropriate support.

Option C suggests that a child with mental retardation has a mental age equal to their chronological age. Mental retardation is not defined in terms of mental age matching chronological age. Instead, it focuses on an individual's intellectual functioning and adaptive behavior, which are assessed using standardized tests.

Option D claims that a child with mental retardation can never function in normal society. This is an incorrect and stigmatizing statement. People with intellectual disabilities can lead fulfilling lives and participate in society with the appropriate support and accommodations.

The most accurate option is B, which states that a child with a diagnosis of mental retardation needs serious learning support in mental ability and behavior. This option aligns with the understanding that individuals with intellectual disabilities often require additional assistance and resources to develop their cognitive skills and adapt to their environment.