Answer:
option (d)
Step-by-step explanation:
Given,
1 ton of a particular item can be stack in= 3 man-hours
36 ton of a particular item can be stack in= 36 x 3 man-hours
= 108man- hours
Number of hours = 6 hours
Number of people =

= 18
Hence, the number of people required is 18.
Therefore, option (d) is correct.