By investing in the education and training of its citizens, or blank capital, Canada has been able to improve its gross domestic product gpd and standard living.

A natural
B Domestic
C Resource
D Human

D Human

The correct answer is D) Human.

To determine this, we should understand what each term refers to:

A) Natural capital: This term typically refers to the stock of natural resources such as forests, minerals, and land. While natural resources are essential for economic development, the question specifically mentions "investing in education and training," which does not align with natural capital.

B) Domestic capital: This term refers to the accumulated stock of physical assets within a country, such as buildings, machinery, and infrastructure. Again, the question emphasizes education and training, which does not fall under the category of domestic capital.

C) Resource capital: This term refers to the stock of resources owned by a country, such as oil reserves, mineral deposits, and agricultural land. While investing in education and training may indirectly impact the utilization of resource capital, it is not the primary means through which it can enhance the country's GDP and standard of living.

D) Human capital: This term refers to the knowledge, skills, abilities, and potential of individuals within a population. By investing in education and training, a country can enhance the skill sets and knowledge of its citizens, leading to a more productive workforce, technological advancements, and innovation. Improvements in GDP and the standard of living are closely tied to the development of human capital.

Therefore, the correct answer is D) Human capital.

D. Human