The answer is: A. collecting data
During this process , researchers would use their observational skills and record every notable occurrence that happen to the variables.
The focus on this process is simply to add all relevant data without making any analyzation. That process come later on after the researchers started to change the variables in order to see whether it would create a correlation.
In Science, a electron in an atom is always negative. The more electrons you have, the more negative a atom is. The more protons (Positives) you have, the more positive a atom is. To balance an atom out, have the same amount of Electrons and Protons.
The correct answer is "coarctation of the aorta". In coarctation of the aorta, there is an abnormal narrowing of the aorta, most commonly in the abdominal aorta, which compromises blood flow from going into the lower extremities. Patients with coarctation of the aorta most commonly presents with tachypnea as this is a high pressure congenital heart defect which makes breathing harder for the baby; diminished femoral pulses and poor lower body perfusion as the narrowing compromises blood flow. In physical examination, there will be a narrow ankle-brachial index, or the difference between the pulse pressures of the ankle (lower extremity) and the brachium (upper extremity).
the answer is c. hydrogen bonding