A) Each person has 5 copies of this gene that may be the same or different.
B) Each person has 2 copies of this gene that may be the same or different.
C) Each person has 5 different genes that code for 5 different proteins.
D) Each person has one gene with only one copy to make one type of protein.
In order to answer this question, we should try the method of cancellation method for the given choices.
Alleles are defined as an alternative form of a gene which is located in a specific portion in the chromosomes. Allele is one variant of a particular gene. Organisms always have a pair of alleles for each trait, it may be the same or different. More often, alleles is more connected with trait rather than encoding of proteins. So we could disregard letter C and D for a while.
Although there are five different alleles for those specific genes, not all of those can be in a single person. Each person has two copies of that particular gene - one from the mother and one from the father. It may be the same or different. So the best answer is letter B.