What is the reason for gain of foreign exchange?
i. Exports
ii. Influx of investment
iii. Import
iv. Grants from rest of the world

i, ii, iv

Gain of foreign exchange means inflow of foreign exchange. Imports cause outflow of foreign exchange i.e. loss of foreign exchange. Exports, grants from rest of the world and influx of investment means inflow of foreign exchange. Influx means inflow.