On which of the following days is National Technology Day celebrated every year?

According to the Ministry of Finance’s Monthly Economic Review, which of the following is the state with the highest revenue deficit?

In which of the following cities was India’s first International Ophthalmology Research Conference held?

In which of the following countries was the first international conference on moving away from fossil fuels held? 

Where is the headquarters of the South Coast Railway, the 18th railway zone of Indian Railways, located?