In nucleic acid, the sequence is:
A.Phosphate base sugar
B.Sugar phosphate base
C.Phosphate sugar base
D.Base phosphate sugar

Hint: We have to know that nucleic acids are the biopolymers, or large biomolecules, that is necessary to all known forms of life. The two major types of nucleic acids are deoxyribonucleic acids (DNA) and ribonucleic acid (RNA).

Complete step by step answer:
We can define Nucleic acids as naturally occurring chemical compounds which serve as the primary information-carrying molecules in cells. They perform a significant role in directing synthesis of protein.
We can say the basic structure of Nucleic acids is long chainlike molecules that contain a sequence of identical building blocks known as nucleotides. Each nucleotide has a nitrogen-comprising aromatic base linked to a pentose (five-carbon) sugar. The sugar is bonded to a phosphate group.
Each nucleic acid has four of five possible nitrogen-containing bases:
1.Adenine (A)
2.Guanine (G)
3.Cytosine (C)
4.Thymine (T)
5.Uracil (U)
We can call Adenine and Guanine as purines. Cytosine, Uracil, and Thymine are known as pyrimidines. The bases Adenine, Guanine, Cytosine, and Thymine are present in all nucleic acid. But in RNA, instead of thymine the base uracil is present. The structures of all nitrogen-containing bases are given below as,

Nucleotides are monomers from which Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are made. Every nucleotide has three components: 5-carbon sugar, phosphate group, and a nitrogenous base. If the sugar present is deoxyribose, the polymer is DNA. The polymer is RNA, then the sugar present in ribose.
In nucleic acid, the sequence is phosphate group, sugar and base.
The given image shows how nitrogen containing bases are present in DNA molecules.



So, the correct answer is Option C.

Note:
We have to know DNA is the nucleic acid which keeps the genetic information. RNA is the nucleic acid that accounts for utilizing the genetic information in DNA to synthesize proteins.