Answer:
Lian, Aida, Dipak, Brian
Step-by-step explanation:
The mechanical advantage of a machine is defined as the ratio of the output force to the input force.
Brian,

Lian,

Dipak,

Aida,

So, form above data it is clear that the mechanical advantage of Lian's machine is least while Brian's machine is greatest.
Hence, the correct order is (d) " Lian, Aida, Dipak, Brian ".