Which one of the following crosses will have a $1:1:1:1$ ratio of progeny?

In Duroc-Jersey hogs,skin color is determined by two pairs of alleles,$R/r$ and $S/s$. Any genotype containing at least one dominant $R$ allele and one dominant $S$ allele results in a red skin color. $A$ double recessive genotype $(rrss)$ results in a white skin color. All other genotypes result in a sandy skin color. If a Duroc-Jersey hog with the genotype $RrSs$ is crossed with a hog having the genotype $rrss$,what will be the phenotypic ratio of the offspring?

The probability of the genotype $TTrr$ in the $F_2$ generation of a dihybrid cross is:

In a dihybrid cross between $AABB$ and $aabb$,the $F_2$ generation produces offspring with genotypes $AABB$,$AABb$,$AaBB$,and $AaBb$. What will be their phenotypic ratio?

In a plant,red fruit $(R)$ is dominant over yellow fruit $(r)$ and tallness $(T)$ is dominant over shortness $(t)$. If a plant with $RRTt$ genotype is crossed with a plant that is $rrtt$,what will be the phenotypic ratio of the offspring?

When tall plants with red flowers were crossed with dwarf plants having white flowers,Mendel found the phenotypic ratio of the $F_2$ progeny to be: