When a violet flower of unknown genotype is crossed with white flower, the progenies are violet and white in equal proportion. Then read the following statements
(i) This is called test cross
(ii) Unknown flower is heterozygous
(iii) Unknown flower is heterozygous
(iv) This test is used to determine the phenotype of the plant at `F_(2)`.
(v) In test cross, violet or white flower is crossed with the recessive parent instead of self-crossing.
Select the incorrect statement :

Options

A. iii, iv, v
B. ii, iv
C. i, ii, v
D. ii, iv, v

Explanation

To solve the question, we need to analyze the given statements regarding the cross between a violet flower of unknown genotype and a white flower. The progeny produced are in equal proportions of violet and white flowers.

### Step-by-Step Solution:

1. **Understanding the Cross**:
- We have a violet flower with an unknown genotype (let's denote it as V?) crossed with a white flower (which we can assume is homozygous recessive, ww).
- The progeny are in equal proportions of violet and white flowers.

2. **Determining the Genotype of the Violet Flower**:
- Since the progeny are in equal proportions (1:1 ratio), this indicates that the violet flower must be heterozygous (Vv).
- If it were homozygous (VV), all progeny would be violet.

3. **Evaluating the Statements**:
- **Statement (i)**: "This is called test cross."
- Correct. A test cross involves crossing an individual of unknown genotype with a homozygous recessive individual.

- **Statement (ii)**: "Unknown flower is heterozygous."
- Correct. As established, the unknown violet flower must be heterozygous (Vv).

- **Statement (iii)**: "Unknown flower is heterozygous."
- Correct. This is a repetition of statement (ii).

- **Statement (iv)**: "This test is used to determine the phenotype of the plant at F2."
- Incorrect. The test cross determines the genotype of the F1 generation, not F2.

- **Statement (v)**: "In test cross, violet or white flower is crossed with the recessive parent instead of self-crossing."
- Correct. This is a definition of a test cross.

4. **Identifying the Incorrect Statement**:
- The incorrect statement among the options is **(iv)**, as it incorrectly states that the test cross is used to determine the phenotype at F2.

### Final Answer:
The incorrect statement is **(iv)**: "This test is used to determine the phenotype of the plant at F2."