Select the option that correctly fills the blanks in the following statements.
i) The phenomenon of physiological change occuring in plants in response to relative length of day and night is called --------
ii) --------- induces parthenocarpy in grapes
iii) Requirement of low temperature treatment for flowering in some plants is called-------
iv) ------- Induces growth in axillary buds

Options

A. (i)-photoperiodism, (ii) - cytokinin, (iii) - vernalisation, (iv)- Auxin
B. (i) - photoperiodism, (ii) - Auxin, (iii) - vernalisation, (iv)-cytokinin
C. (i) - vernalisation, (i) -Auxin, (iii) - photoperiodism, (iv)-cytokinin
D. (i) - vernalisation, (ii) - cytokinin, (iii) - photoperiodism, (iv)- Auxin

Answer

To answer the question, we need to fill in the blanks with the correct terms based on the provided statements related to plant growth and development.

### Step-by-Step Solution:

1. **Identify the first statement**:
- The statement is about the physiological change in plants in response to the relative length of day and night.
- The correct term for this phenomenon is **Photoperiodism**.

2. **Identify the second statement**:
- The statement asks which substance induces parthenocarpy in grapes.
- The correct answer is **Auxin**, as it is known to promote parthenocarpy in many plants, including grapes.

3. **Identify the third statement**:
- This statement refers to the requirement of low temperature treatment for flowering in some plants.
- The term that describes this requirement is **Vernalization**.

4. **Identify the fourth statement**:
- The statement is about the hormone that induces growth in axillary buds.
- The correct hormone for this function is **Cytokinins**.

### Final Answers:
i) Photoperiodism
ii) Auxin
iii) Vernalization
iv) Cytokinins