How are red blood cells able to move through narrow vessels to carry oxygen throughout a multicellular organism? (1 point) a)They are flexible because they lack a plasma membrane. b)They are small because they lack a nucleus. c)They are long and thin with a tail-like end. d)They are small because their organelles are smaller than those of other cells.

The correct answer is - option B. They are small because they lack a nucleus.

Explanation:

Red blood cells or erythrocytes are specialized cell that produce in bone marrow and have specific role such as carrying oxygen from lungs to deliver it to the various organs and carry out carbon dioxide.

In mammals these cells lack cell organelles such as nucleus and mitochondria, a major factor that determined its smaller size. The size of RBC are move through narrow vessels throughout a organism because of its specific size and shape that provide it space for hemoglobin and allow to be flexible and bend to move through narrow vessels.

Thus, the correct answer is : option B. They are small because they lack a nucleus.

format change of dna.  

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs