A Plantlike Organism on the Planet Pandora Can Have Three

Multiple Choice

A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves,due to an allele (a) of gene A;a feathered stem,due to an allele (b) of gene B;and hollow roots,due to an allele (c) of gene C.The three genes are linked and recombine.
A geneticist did a testcross with an organism that had been found to be heterozygous for the three recessive traits and was able to identify progeny of the phenotypic distribution (+ = wild type) shown in the figure below.
Which of the following are the phenotypes of the parents in this cross?

A) 2 and 5
B) 1 and 6
C) 4 and 8
D) 3 and 7
E) 1 and 2