The correct answer is option 'C' - 2, 3 and 4 only.

The Mature Harappan phase refers to the period when the Harappan civilization reached its peak and was characterized by the development of urban centers, sophisticated planning, and advanced technologies. Mehergarh, on the other hand, is associated with the Early Harappan phase.

Explanation:

1. Mehergarh:
- Mehergarh is located in present-day Pakistan and is one of the earliest known agricultural settlements in South Asia.
- It dates back to approximately 7000 BCE and is associated with the Early Harappan phase, which predates the Mature Harappan phase.
- Mehergarh is significant as it provides insights into the development of agricultural practices and the gradual transition from a nomadic lifestyle to settled farming communities.

2. Harappa:
- Harappa is one of the most famous archaeological sites of the Indus Valley Civilization and is located in present-day Pakistan.
- It was one of the major urban centers during the Mature Harappan phase, which spanned from around 2600 BCE to 1900 BCE.
- Harappa is known for its well-planned layout, with a grid-like pattern of streets, well-built houses, and advanced drainage systems.
- The discovery of seals, script-like symbols, and various artifacts indicate a complex social and economic system.

3. Mohenjo-daro:
- Mohenjo-daro, located in present-day Pakistan, was another prominent urban center of the Indus Valley Civilization during the Mature Harappan phase.
- It flourished from approximately 2600 BCE to 1900 BCE and is considered one of the largest settlements of the ancient world.
- Mohenjo-daro had a highly sophisticated and well-planned layout, with well-built houses, public baths, granaries, and an advanced drainage system.
- The discovery of a large number of artifacts, including sculptures, pottery, and jewelry, suggests a thriving artistic and craft industry.

4. Lothal:
- Lothal is an ancient city located in present-day Gujarat, India, and was an important center of trade and commerce during the Indus Valley Civilization.
- It was part of the Mature Harappan phase and was occupied from approximately 2500 BCE to 1900 BCE.
- Lothal is known for its well-developed dockyards, indicating its maritime trade connections.
- The site also provides evidence of advanced metallurgical techniques and a centralized authority involved in the administration of trade and commerce.

In conclusion, Mehergarh is associated with the Early Harappan phase, while Harappa, Mohenjo-daro, and Lothal are part of the Mature Harappan phase. Therefore, the correct answer is option 'C' - 2, 3 and 4 only.