An example of an incomplete dominant trait, a codominant trait, and a sex-linked trait?

If two plants were crossed to produce a yellow and blue flower, and if the alleles of the gene responsible for petal color were dominant in nature, the flower produced by the progeny plant would either be yellow with blue spots or blue with yellow spots. http://www.softschools.com/examples/science/codominance_examples/477/

Sex linked Trait ; Red-green colorblindness – Inability differentiate between read and green  

http://kmbiology.weebly.com/sex-linked-traits---notes.html

answer; the correct answer is desert plants;

a and c are the answeres