Not to be too picky, but the question ought to say a positively charge ion rather than atom.
I will assume that is what you mean. An ion, using ordinary means, will be positive if it loses electrons (which are negative).
An ion can never gain protons. Left alone, the nucleus will remain unchanged for the rest of eternity. D is wrong.
C is wrong. If electrons are gained, the ion will go negative.
B is wrong for the same reason D is. An ion can't gain protons and it can't lose them.
A is the answer.
The right answer is a person has more than two alleles for a certain trait.
Duplication is a genetic mutation characterized by the doubling of genetic material on a chromosome. There are several mechanisms that result in the duplication of either a large chromosomal portion, a gene, or a nucleotide sequence.
