To solve this problem, we need to determine the genotypic ratio of the F₂ generation when a tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant.$\newline$Let's break down the steps:$\newline \bullet$A tall true breeding plant is homozygous dominant (TT), and a dwarf true breeding plant is homozygous recessive (tt).$\newline \bullet$When these two plants are crossed, the F₁ generation will all be heterozygous (Tt) and phenotypically tall.$\newline \bullet$When the F₁ plants (Tt) are selfed, the F₂ generation will have the following genotypes:$\newline$ - TT (homozygous tall)$\newline$ - Tt (heterozygous tall)$\newline$ - tt (homozygous dwarf)$\newline$The genotypic ratio of the F₂ generation is:$\newline \bullet$1 TT : 2 Tt : 1 tt$\newline$This corresponds to Option 1: 1 2 1 Tall homozygous Tall heterozygous Dwarf.$\newline$However, the question asks for the phenotypic ratio, which is:$\newline \bullet$3 Tall : 1 Dwarf$\newline$This corresponds to Option 3: 3 1 Tall Dwarf.$\newline$Therefore, the correct option is Option 3.