Answer : 1. "The value of exports to be added and the value of imports to be subtracted"
Explanation :

National Income of a country can be defined as the total market value of all final goods and services produced in the economy in a year. In expenditure method, the National Income is measured by adding up the four flows, - namely C, I, G, X and M.

Thus, Y = C+1+G + (X-M) + (X- M) Where,

C = Total consumption expenditure

I = Total investment expenditure

G = Total government expenditure

X = Export,

M = Import