Smallest flower is :

Options

A. Wolffia
B. Lotus
C. Rafflesia
D. Brassica

Answer

To determine the smallest flower, we will analyze the information provided about various flowers and their sizes.

### Step-by-Step Solution:

1. **Identify the Options**: The question asks for the smallest flower, so we need to consider the sizes of different flowers mentioned, specifically Vulfia, Lotus, Rafflesia, and Brassica.

2. **Examine Vulfia**: Vulfia is described as an aquatic plant with a length ranging from 0.4 mm to 1.3 mm. It is noted to be the smallest flower.

3. **Examine Lotus**: The Lotus flower has a height of 18 to 60 inches and a diameter of 2 to 3 mm. This size is significantly larger than that of Vulfia.

4. **Examine Rafflesia**: Rafflesia is known for being the largest flower, with sizes that can grow up to 3 feet in length and weigh up to 15 lbs. This clearly indicates it is not the smallest flower.

5. **Examine Brassica**: Brassica can grow up to 60 cm in length, which also makes it larger than Vulfia.

6. **Conclusion**: After comparing the sizes, it is clear that Vulfia, with its size of 0.4 mm to 1.3 mm, is the smallest flower among the options provided.

### Final Answer:
The smallest flower is Vulfia.