When a homozygous tall plant is crossed with a homozygous dwarf plant,what is the percentage of dwarf progeny obtained in the $F_1$ generation by Mendel (in $\%$)?

In his classic experiments on pea plants,Mendel did not use .......... .

$A$ gene is said to be dominant,if

Genes are

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: In an experiment, Mendel observed that the $F1$ progeny plants are all tall and none are dwarf.
Reason $R$: Stem height is a contrasting trait, with tall being dominant and dwarf being recessive.
In the light of the above statements, choose the most appropriate answer from the options given below:

To determine the genotype of an offspring,which cross should be performed?