Final Answer:
The Framingham Heart Study is a renowned cardiovascular research initiative initiated in 1948 in Framingham, Massachusetts, aiming to identify risk factors for heart disease. Regarding hydrogen bonding in DNA, it is strongest between adenine and thymine.
Step-by-step explanation:
The Framingham Heart Study is a landmark research project initiated to investigate cardiovascular health and disease. Launched in 1948, it has significantly contributed to identifying major risk factors for heart disease, including hypertension, cholesterol levels, smoking, obesity, and diabetes.
Regarding hydrogen bonding in DNA, the correct pairing is crucial for the stability of the double helix structure. Adenine forms two hydrogen bonds with thymine, while guanine forms three hydrogen bonds with cytosine. The hydrogen bonding between adenine and thymine is essential for maintaining the structural integrity of the DNA molecule.
Option D (adenine and thymine) is the answer.