Explanation:

The larva of a butterfly is called a caterpillar. It is the first stage of the butterfly's life cycle and undergoes a complete metamorphosis to transform into an adult butterfly. Here is a detailed explanation of why the correct answer is option 'D' - Caterpillar.

Life Cycle of a Butterfly:
1. Egg: The life cycle of a butterfly starts with an egg. A female butterfly lays eggs on the leaves of plants. Each species of butterfly has its preferred host plants on which it lays eggs.
2. Caterpillar: Once the egg hatches, a larva emerges, which is commonly known as a caterpillar. Caterpillars have long segmented bodies with multiple pairs of legs. They are voracious eaters and feed on the leaves of the host plant.
3. Pupa: After the caterpillar reaches its full size, it forms a protective casing called a chrysalis or pupa. Inside the pupa, the caterpillar undergoes a process called metamorphosis, where it transforms into an adult butterfly.
4. Adult Butterfly: Finally, the adult butterfly emerges from the pupa. It takes a short while for the wings to expand and dry before the butterfly can fly. The adult butterfly then searches for a mate to reproduce and continue the life cycle.

Why is the answer 'D' - Caterpillar?
The larva of a butterfly is called a caterpillar because it has distinct characteristics that set it apart from other insects. Here are a few reasons why the answer is 'D' - Caterpillar:

1. Physical Appearance: Caterpillars have a unique body structure with a long, segmented body and multiple pairs of legs. They also have a distinct head with chewing mouthparts.
2. Feeding Behavior: Caterpillars are known for their voracious appetite and their primary purpose during this stage is to eat and grow. They consume large amounts of plant material, mainly leaves, to fuel their growth.
3. Distinct Life Stage: The caterpillar stage is a crucial part of the butterfly's life cycle. It is the stage where the insect undergoes most of its growth and development before entering the pupal stage.
4. Transformation: Caterpillars go through a remarkable transformation during metamorphosis. They completely change their body structure, including the formation of wings, which enables them to fly as adult butterflies.

In conclusion, the correct answer is option 'D' - Caterpillar because it is the larval stage of a butterfly, characterized by its physical appearance, feeding behavior, and role in the life cycle.

Butterfly means caterpillar