How Does Sickle Cell Hemoglobin Result in Oxygen Deprivation to Vital

How does sickle cell hemoglobin result in oxygen deprivation to vital organs?

A) It carries oxygen in the blood normally, but once the oxygen is released, the misshapen HbS molecules tend to stick together into fibers, altering the shape of red blood cells such that they tend to clog, and blood (and therefore oxygen) flow is impaired.
B) It's missing the amino acid that carries one of the four oxygen molecules that normal HbA can carry, so the vital organs get one less oxygen molecule per red blood cell passing by.
C) It carries oxygen like normal HbA, but the fibers that it forms hold the oxygen in such a way that the red blood cells don't let it go and therefore oxygen flow is impaired.
D) Because of its weird shape, it can't carry oxygen at all and so oxygen flow is impaired.
E) It carries oxygen in the blood normally but the shape of the abnormal HbS results in fibers of oxygen rather than molecules and the organs can't absorb oxygen in this form.