The law of dihybrid cross proves which of the following?

In humans, brown eyes $(B)$ are dominant over blue $(b)$ and dark hair $(D)$ are dominant over red hair $(d)$. A man with brown eyes and red hair marries a woman with blue eyes and dark hair. They have two children; one resembles the man (brown eyes, red hair), and the other resembles the woman (blue eyes, dark hair). What are the genotypes of the man and the woman?

The gametes of an individual with genotype $AaBb$ can be:

In a plant with genotype $RrYy$,if self-pollination occurs,what will be the ratio of the following genotypes: $RRYY, RrYY, RRYy, RrYy$?

If a plant having yellow and round seeds was crossed with another plant having green and wrinkled seeds,then the $F_{1}$-progeny are in the ratio:

In a dihybrid cross between individuals with genotypes $TtRr$,if the total number of offspring is $16$,identify the number of individuals with genotypes $TtRr$ and $TtRR$ among them.