Which of the following items are included in the estimation of national income? Select the correct answer using codes given below :
(a) Bonus
(b) Gratuity
(c) Value of production for self consumption
(d) Imputed rent of owner occupied house
1
None of these items
2
only (a)
3
only (a) and (b)
4
(a), (b), (c) and (d)