Triglycerides are composed of:

A. compounds that are ionically bonded together: Ionic compounds (like NaCl) dissociate easily in water because water's polarity can separate the positive and negative ions.
B. carbon-hydrogen chains, like saturated fats: These are nonpolar covalent compounds and are hydrophobic, so they don’t dissolve or dissociate well in water.
C. compounds that are covalently bonded together: Covalent bonds are strong and molecules remain intact in water; they don’t dissociate into ions.
D. compounds with covalent and some polar covalent bonds: These might partially dissolve but don’t dissociate readily into ions like ionic compounds do.

A. As body temperature rises, sweating occurs to cool the body:
An example of negative feedback, where the body counters a change to restore normal state.

B. After drinking large amounts of water, urine output decreases to raise blood volume:
Urine output would actually increase to excrete the excess water and maintain volume.

C. Decreases in blood pressure cause a corresponding decrease in heart rate:
A decrease in blood pressure should cause the heart rate to increase (compensatory response).

D. As blood pressure falls, blood flow to the heart decreases:
The body usually increases heart rate and vasoconstriction to maintain cardiac output.