Final answer:
Understanding genetic variations aids in tailoring personalized treatments and predicting disease risks. Variations can affect both disease susceptibility and drug sensitivity through pharmacogenomics. Therefore, 'All are correct' is the best answer to why knowledge of genetic variations can improve patient treatment efficiency.
Step-by-step explanation:
Understanding genetic variations in human diseases can make patient treatment more efficient for several reasons. First and foremost, certain gene variants can put an individual at a higher risk of developing a specific disease; others may increase the risk only marginally. This risk assessment is crucial for predictive health care. Moreover, a patient's heredity can lead to a predisposition for certain genetic disorders. Secondly, some genetic variants can influence the way an individual responds to medications, a field known as pharmacogenomics. This means that patients may require personalized medication dosages or choices based on their genetic makeup to optimize efficacy and minimize side effects.
Therefore, the correct answer to the question would be option C, 'All are correct.' Genetic testing and understanding an individual's DNA sequence play significant roles in predicting disease risk and tailoring personalized medicine. Such information aids in the prediction of diseases that might arise from single gene mutations as well as complex multifactorial conditions that are influenced by a combination of genetic and environmental factors.