Explanation:
Pseudopodia are temporary extensions of the cell membrane and cytoplasm of amoeboid cells. They are used by amoeboids for various functions, including locomotion and the ingestion of food particles.

Locomotion:
- Amoeboids, such as amoebas, use pseudopodia for locomotion.
- The formation of pseudopodia allows the amoeboid to extend its cytoplasm in a specific direction, pushing against the substrate and propelling the cell forward.
- By continuously forming and retracting pseudopodia, the amoeboid is able to move in a process known as amoeboid movement.

Ingestion of Food:
- Amoeboids use pseudopodia to capture and engulf food particles.
- When a food particle is detected, the amoeboid extends pseudopodia around the particle, forming a temporary food vacuole.
- The pseudopodia then fuse together, enclosing the food particle within the cell.
- The food vacuole then fuses with lysosomes, which contain digestive enzymes, allowing the food to be broken down and nutrients to be absorbed by the cell.

Locomotion and Ingestion of Food:
- Pseudopodia serve a dual function in amoeboids, facilitating both locomotion and the ingestion of food.
- The extension and retraction of pseudopodia allow the amoeboid to move towards a food source, capture the food particles, and transport them towards the cell body for digestion.
- This efficient use of pseudopodia enables the amoeboid to both find food and move towards favorable conditions for survival.

Performing Metabolic Reactions:
- While pseudopodia primarily aid in locomotion and the ingestion of food, they also play a role in performing metabolic reactions.
- The extension of pseudopodia allows the amoeboid to explore the environment and encounter potential sources of nutrients.
- Additionally, the pseudopodia can be involved in the exchange of gases and waste products with the surrounding medium, facilitating metabolic processes within the cell.

Therefore, pseudopodia help amoeboids in both locomotion and the ingestion of food, making option 'C' the correct answer.