The correct answer would be recessive trait phenotype.
Explanation:
The cross between homozygous dominant and homozygous recessive result in all dominant phenotypically dominant as they have heterozygous dominant which means they have one allele of dominant trait and other allele of the recessive trait.
Test cross is the cross between dominant individual of F1 offspring with the phenotypically recessive. As found F1 is heterozygous so cross with recessive will result in 50% recessive and 50% dominant phenotypically.
Thus, the correct answer is recessive that was not present in F1 generation.
