Answer:
The correct answer is B. A gamete carries one allele for a gene.
Explanation:
Gamete (also called sex cell or reproductive cell) is a haploid cell (having half number of chromosome as compared to the parent cell) that is produced through a cell division, termed as meiosis in sexually reproducing organisms.
According to the Law of segregation given by Gregor Mendel-
During the process of gamete formation, the two alleles of each gene segregate from one another so that a gamete carries one allele for a gene.
Thus, option B) is the right answer.