What is the phenotypic ratio of a monohybrid cross?

Monohybrid cross refers to a cross between two homozygous parent plants. 

On crossing homozygous tall and dwarf pea plants, the first generation produced progenies which were heterozygous tall.

On selfing these heterozygous tall, 4 progenies were obtained differing in external and genetical characteristics.

The phenotype is the external appearance.

On observing external features, 3 plants were tall (1 homozygous tall and 2 heterozygous tall) while remaining 1 is homozygous dwarf.

The phenotypic ratio in this cross ‘F₂ ‘ is 3:1, and the genotypic ratio is 1:2:1.

The correct answer is '3:1'.

The correct option is Option B, i.e., 3:1.