By using a knapsack sprayer, a man can spray over the area of about __________
(a) 1 ha per day
(b) 0.75 ha per day
(c) 1.25 ha per day
(d) 0.4 ha per day
I have been asked this question in unit test.
My question is taken from Plant Protection Equipments in portion Plant Protection Equipments of Farm Machinery