What is the function of vena cava?
hello didi and twinkle ​

A large vein that carries blood to the heart from other areas of the body. The vena cava has two parts: the superior vena cava and the inferior vena cava. The superior vena cava carries blood from the head, neck, arms, and chest.

The inferior vena cava is a vein. It carries deoxygenated blood from the lower half of the body to the right atrium of the heart. The corresponding vein that carries deoxygenated blood from the upper half of the body is the superior vena cava.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.