The correct answer is option 3: 70. In the context of politics and government, an assembly segment refers to a specific geographical area or constituency that has a representative in the legislative assembly. In the case of Delhi, which is the capital city of India, it is divided into several assembly segments. These segments are responsible for electing Members of the Legislative Assembly (MLAs) who represent the interests of the people in their respective areas.

The other options - 50, 60, and 40 - are incorrect and do not represent the total number of assembly segments in Delhi.