About 3 weeks ago, you started lifting weights at the student rec center. You are disappointed that you have not seen the results you were anticipating. You can lift more now than you could when you started, but you were hoping to tone and define the muscles in your arms, back, and abs. Perhaps you need more protein. Everywhere you look there are numerous advertisements for protein and amino-acid supplements, but they are expensive. What would be the best choice for optimal nutrition support to your weight-training regimen and provide support as to why you would choose this method?
A. Take individual amino-acid supplements.
B. Take whey protein supplements.
C. Increase your consumption of animal protein.
D. Consume a diet that provides 15-30% of calories from a variety of sources of protein.