Which of the following could be a cause of intellectual disability?

Genetic abnormalities can indeed be a significant cause of intellectual disability. These abnormalities may manifest in various ways, such as chromosomal disorders like Down syndrome or single-gene abnormalities that impact brain development and function. Genetic factors can affect cognitive abilities and developmental processes, leading to varying degrees of intellectual disabilities.

While the other factors like nutrition during childhood can also have an impact on cognitive development, they do not inherently cause intellectual disability in the same direct manner as genetic factors. High levels of exercise, on the other hand, are generally associated with various health benefits and are not recognized as a cause of intellectual disability. Similarly, while the education level of parents can influence a child's developmental environment and opportunities, it is not a direct cause of intellectual disabilities in the same way genetic abnormalities can be classified.