Final answer:
National or ethnic origin and family status are commonly protected grounds against discrimination in all Canadian human rights acts, while language may be more region-specific and age protection can vary.
Step-by-step explanation:
In Canada, human rights acts are designed to prevent discrimination on various grouds. While specific protections can vary by province or territory, there are certain grounds for discrimination that are commonly protected across all human rights acts in the country. Among the options provided, national or ethnic origin (c) and family status (d) are frequently found as prohibited grounds in all Canadian human rights legislation. Language (b) may also be protected, but it is more specific to certain regions, such as Quebec. Age (a) as a protected ground can vary, as some jurisdictions may specify particular age ranges for protection against age discrimination.