The pineapple which under natural condition is difficult to blossom has been made to produce fruits throughout the year by application of

Options

A. NAA, 2,4-D
B. phenyl acetic acid
C. cytokinin
D. none of these

Answer

To solve the question regarding how to make pineapple produce fruits throughout the year, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Problem**: The question states that pineapples have difficulty blossoming under natural conditions, and we need to identify a substance that can help induce flowering throughout the year.

2. **Identify the Options**: The options provided are:
- A) NaA (Naphthalene acetic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid)
- B) Phenylacetic acid
- C) Cytokinin
- D) None of these

3. **Review Plant Hormones**:
- **Auxins**: These are plant hormones that promote growth and are involved in various developmental processes. NaA and 2,4-D are synthetic auxins.
- **Cytokinins**: These hormones promote cell division and growth but are not specifically known for inducing flowering in pineapples.
- **Phenylacetic Acid**: This is an organic compound that can aid in plant growth but is not primarily used for inducing flowering.

4. **Determine the Correct Answer**:
- Among the options, NaA and 2,4-D are known to be effective in promoting flowering and fruiting in certain plants, including pineapple. They help in the process of plant propagation and can stimulate the flowering process.

5. **Conclusion**: Based on the information reviewed, the correct answer to the question is **A) NaA and 2,4-D**.